The article presents and discusses the results of the evaluation of the effects of an intervention to strengthen socio-emotional skills carried out in Colombia in 2019 as part of the international cooperation project "La Paz Unica Esperanza Para el Desarrollo Economico y Social" (PUEDES). The evaluation is carried out with the difference-in-difference method, on a group of 754 adolescents aged between 10 and 18, attending secondary school in the Department of Putumayo. The competences being assessed are self-esteem, regulation of positive and negative emotions and empathy. The results show that the effects were positive in all skills and, observing the differentiated effect by gender, it was found that it was more intense among girls than boys. Furthermore, participatory processes have produced positive effects especially in girls, in particular as regards the management of negative emotions, confirming the relevance of the gender variable in this type of process. [ABSTRACT FROM AUTHOR]