Introduction: In the "new ecology of learning" it is becoming crucial to trace the paths of learning experiences that students develop both in school and outside it. Few research studies have focused on out-of-school activities. In this paper, we explore differences between children and adolescents in their participation through 26 out-of-school activities, and their subjective perception of the learning thus derived. Method: We designed a questionnaire to explore participation in out-of-school activities and the subjective value that students attribute to their learning experiences. The list of activities was determined through thematic analysis of 17 previous focus groups. Participants are 946 children, aged either 10 or 16, from public schools in Catalonia. Participation is analysed according to age, gender, SES, and students' area of residence. Data analysis is performed with SPSS software. Results: Trends in participation in out-of-school activities appear to differ according to participants' age and gender, whereas factors such as SES and area of residence have a very limited influence. Engagement in out-of-school activities shows a developmental pattern according to participants' age, as well as important gender-related differences (males are overrepresented in "sports" and "playing video games", while females show a greater preference for social- or academic-oriented activities). The whole sample rate academic-related activities as more important than other informal kinds of activities from which they also learn. Conclusions and Discussion: Schools need to be aware of the influence that gender stereotypes and social discourses about formal learning can have on the decision making of students. New ways of validating non-formal and informal learning experiences should be implemented to recognise and increase the social visibility of other formative experiences developed outside formal contexts.