The objective of the research was to determine the effectiveness of the “We live happily” program in the development of social skills of the students of the fourth degree of the Almirante Miguel Grau Seminario Educational Institution. The research approach was quantitative, the design was experimental and the type was pre experimental. The sample was made up of 32 students in the fourth grade of the elementary level. The instrument used was the Social Skills Questionnaire designed by the Ministry of Health. The main result found indicates that the level of social skills development of the students in the pretest was regular (48.5%) while in the posttest it was the high level (51.5%). Therefore, it is concluded that the application of the “We live happily” program is effective because it managed to significantly develop the social skills of the Fourth Grade students of the Admiral Miguel Grau Seminary Educational Institution.