RESUMENAnte the obvious manifestation of a phenomenon of violence called bullying (bullying) in schools across the country, which has put on red alert to the educational system; It seeks that the teacher is at the forefront in situations of this kind. Requiring new strategies for teaching and learning that points towards the improvement of the interpersonal relationships of the learners, proposing the formation of the student, based on the practice of values and integration and mutual aid as a main point. Therefore the present study general objective is to "determine the influence of the application of strategies of cooperative learning in the decrease of the Bullying of students of the 5th grade of the I.E. Auxiliadora Mara from Piura. It has been considered a sample of 17 students, which are formed by 9 women and 8 men; they were chosen because they are students with high levels of bullying in its different dimensions. Survey technique, was used to collect the data, resulting in the questionnaire, which was previously validated instrument. This instrument was applied to students in order to collect specific data on behavior of physical, verbal, social and psychological violence in the classroom. To process data has been used analysis of descriptive and inferential statistics, such as measures of central tendency, mainly: media, fashion, and median of variability such as the range, standard deviation, and variance. In inferential statistics, Student's T, has been considered to determine the significance of the results. At the conclusion of the study is resulted, in the classroom of 5th grade of the I.E.P. "Mara auxiliadora" managed to curb Bullying and this could demonstrate the significance of the application of cooperative strategies through the program "working together cooperative learning strategies, we say No to bullying" keywords : bullying, verbal, physical, social, psychological, cooperative learning strategies