1. January 2008

2. Safe Harbor Statement This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995.Such statements include, but are not limited to, statements about Mercantile Bancorp Inc.s plans, objectives, expectations and intentions and other statements that are not historical facts.Such statements are based upon the current beliefs and expectations of Mercantiles management and are subject to significant risks and uncertainties. Actual results may differ materially from those set forth in the forward-looking statements. The following factors, among others, could cause actual results to differ from those set forth in the forward-looking statements: changes in the interest rate environment; changes in the securities and real estate markets; increased competition and its effect on pricing, spending, third-party relationships and revenues; and the risk of new and changing regulation in the U.S. Additional factors that could cause the Companys results to differ materially from those described in the forward-looking statements can be found in the 2006 Annual Report on Form 10-K, or on the September 30, 2007 Form 10-Q of Mercantile (included under the heading Forward-Looking Statements), filed with the Securities and Exchange Commission (SEC) and available at the SECs internet site ( http://www.sec.gov ). Any forward-looking statements today speak only as of today, and the Company assumes no obligation to update the forward-looking statements or to update the reasons why actual result could differ from those contained in the forward-looking statements. 3.

Multi-bank holding company based in Quincy, IL

$1.6 billion in assets

Over 450 employees

31 locations in 23 communities throughout 4 states

Concentrated presence in West-Central Illinois and Northeastern Missouri

Dynamic, growing trust business

Startup bank investments offer equity gains and lending opportunities

Diversified income sources

Overview 4. Background

Mercantile Trust & Savings Bank founded in 1906

Mercantile Bancorp, Inc. founded in 1983

Began strategic investments in community banks in 1988

Started trading publicly in early 2005

Core holdings in West-Central Illinois, Northeast and Northwest Missouri, Northeast Kansas, and Southwest Florida, investments elsewhere

Acquired and integrated a total of eleven banking organizations since 1983

5. Snapshot

AMEX:MBR

52-Week Range $14.13-$17.77*

Price (12/31/07) $17.45

Book Value Per Share (9/30/07)$12.18

Price/Book 1.43X

Price/Earnings (ttm) 14.19X

Dividend (annualized) $ 0.24

Shares Outstanding 8,709,727

Market Cap $152.0 Million

* Price adjusted for 3/2 split 12/28/07 6. Redefining Community Banking Since 1983 * 7. Illinois Bank Holding Company Founded in 1983

Mercantile Bank Quincy, IL 1983

Marine Bank & Trust Carthage, IL 1991

Perry State Bank Perry, MO 1994

Brown County State Bank Mt. Sterling, IL 1997

Farmers State Bank of No. Missouri Savannah, MO 1999

Heartland Bank Leawood, KS 2004

The Royal Palm Bank Naples, FL 2006

HNB Bank Hannibal, MO 2007

8. Three-Prong Growth Strategy

To Generate Consistent Results with:

Asset growth, stable returns from wholly owned core banks

Revenue, asset and earnings growth enhancement through acquisition

Investment gains through minority equity positions in high-growthde novobanks

9. 10. Core Bank Strategy 11.

Maximize marginsmaintain interest rate risk stabilityallow for individual market economics to influence

New savings, checking products

Expand market share

Bring value to small business accounts

Interest Income Deposits 12.

Expand market share

High levels of customer service win repeat business

Leverage startup bank relationships for loan participation

Maintain high credit quality standards to support steady asset growth and continued asset quality

Interest Income Loans 13. Non-Interest Income

Establish trust department model in key banks: focus on life planning needs

Strategically expand in-bank brokerage

Focus on customer retention, stability

Our best customer is an asset management customer

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Community bank focus, service culture

Local management expertise

Operating efficiencies

Superior Community Bank service

Big bank product offerings

Manage loans and investments to maximize margins, minimize interest rate risk

Operating Philosophy Core Banks 15. Entering New Markets Through Acquisition, Branching 16.

Primary focus on:

Complementary operating characteristics

Compatible management, corporate culture

Growth potential of market

Market size, demographics we can serve

Acquisition and Branching Strategy By focusing on operations, corporate culture and growth potential, we have the flexibility to targetgeographically diversecommunity banks serving growth markets 17. MBR Acquisition, Branching Skills

Management experience

Four acquisitions in eight years

Acquired banks maintain individuality, employees and management

Transition team to smooth employee integration

Experienced technology & ops team

18. 2007 : HNB Financial Services

Hannibal, Missouri-based institution

More than $186 million in assets (9/30/07)

Merging MBR-owned Perry State Bank into HNB creates efficiencies, market share opportunities

Creates continuous 100-mile banking presence from Quincy, IL to St. Louis area

All-cash transaction anticipated to be accretive in 12 months

19. Royal Palm Bank: Southwest Florida

Naples-Marco Island MSA grew 27% (2000-2005)

Forecasted increase from 320,000 residents to 400,000 25%(2006-2010)

Serving Naples, Marco Island, Fort Myers

Avg. household income: $91,000

20. Heartland Bank: Kansas City MSA

Kansas City MO-KS MSA ranked 26 thin nation.Total population 1,934,000. (2005)

Johnson County, KS

• 2006 population 517,000 a 5% increase since 1990 census

• 2003 median household income $63,200 2005 figure is $68,200.

Jackson County, MO

• 2006 population 664,000 a 5% increase since 1990 census.

• Median household income $44,400(2005)

21. De Novo Bank Investments 22. Bank Investments

Integrity Bank Jupiter, FL

Premier Bancshares, Inc. Jefferson City, MO

Premier Community Bank Crestview, FL of The Emerald Coast

Paragon National Bank Memphis, TN

Integrity Bancshares, Inc. Alpharetta, GA

Enterprise Financial Services * Clayton, MO

First Charter Corporation * Charlotte, NC

Solera National Bank Lakewood, CO

Brookhaven Bank Atlanta, GA

Manhattan Bancorp Los Angeles, CA

* Acquisition by divestiture of de novo bank

23. De Novo Bank Investment Strategy

Strategic investments in growing banks serving growing markets

Unconstrained by geographical location of target investments

24. De Novo Investment Benefits

Capital infusion from MBR fuels growth for selected bank investment

Possible loan participation with MBR opens doors to new lending opportunities

Affiliation with established community bank holding company

To Target Investment To Mercantile Bancorp, Inc

Investment position requires no active management involvement

Loan growth

Option to grow equity investment or sell investment, based on maximum shareholder benefit

25. Our Performance 26. Growth Drivers

Continuing demand for service-oriented community banks

MBR lending limit ability due to our collective size

Small business growth continues to drive commercial lending

Robust growth in quality mid-sized markets

Expansion of asset and land management services

27. Total Assets at December 31 (Shown in Million Dollars) *Unaudited 28. Total Loans at December 31 (Shown in Million Dollars) *Unaudited 29. Loan Portfolio

Sept. 30, 2007

(Dollars in Millions)

Commercial and industrial $17215%

Agricultural production 59 5%

Real estate farmland 857%

Real estate construction19016%

Real estate commercial 211 18%

Real estate residential 329 28%

Installment loans to individuals 13611%

Total loans $1,182 100.0%

30. Loan Performance(Shown in Thousand Dollars) 2003-2006 at December 31; 2007 at September 30, 2007 31. Total Depositsat December 31(Shown in Million Dollars) *Unaudited 32. Non-Interest Income at December 31(Shown in Million Dollars) *Unaudited 33.

Asset Management Services

Assets under management and non-interest income grow in direct correlation with one another

Growth strategy includes platforming through our affiliate banks to expand market share

Life Planning Strategies marketing approach to better transition business into asset management services as life cycle ofcustomers mature

St. Charles, MO: opened trust office in 2005; EOY 2006 assets totaled $9.5 million; $14 million EOY 2007

Agri-Business Services: Total Acreage Under Management( Includes both trust and agency-managed acreage. )

2004 23,400 Acres

2005 25,500 Acres

2006 26,400 Acres

2007 25,301 Acres

* Unaudited, as of 12/31/07 34.

Brokerage Services

Reorganizing services under one broker/dealer

Growth strategy includes platforming through affiliate banks to expand market share

Life Planning Strategies marketing approach to better transition business from retail banking throughout life cycle of customer

* Unaudited, as of 12/31/07 35. Net Income at December 31 (Shown in Million Dollars) *Unaudited 36. Return on Average Equity at December 31*Unaudited 37. Stock Price Activity * Price adjusted for previous stock splits. 38. Price/Book Value Perspective

MBR:1.43x book value

NASDAQ Bank Index* 1.29x book value

* Source Bloomberg 1/8/08 ticker CBNK

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Our Goal

Seeking avenues to grow and executing performance as a company of community banks, while raisingawareness of MBR combines the potential to generate value for our investors.

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