The present study set out to evaluate participant responsiveness, one of the main dimensions of implementation quality, in a Socio-Emotional Learning after-school program using Educational Dance activities, Experiencing Emotions, and also to understand its influence on program outcomes. The sample involved 98 middle-school Portuguese pupils, 53 of whom participated in the program and 45 in after-school control sessions. Outcome measures included pre-test and post-test questionnaires of pupils' socio-emotional skills, well-being and school engagement. A self-report item measured pupils' satisfaction at the end of the program, and a checklist measuring attendance and homework completion was filled in by the facilitator at each session of the program and control condition. Results revealed (1) high levels of pupils' satisfaction and attendance, and a medium-high level of homework completion towards the program; (2) that pupils' higher attendance rate in the program predicted higher results in the self-management (p = .04, d = .57; p = .003, d = .87) and social awareness (p = .04, d = .59) SEL domains, emotional (p = .02, d = .67) and psychological (p = .009, d = .76) well-being and school engagement (p = .04, d = .56); (3) that pupils' higher rate of homework completion in the program predicted higher results in the relationship skills SEL area (p = .04, d = .59) and in school engagement (p = .005, d = 1.50); (4) that pupils' from the control condition higher rates of homework completion also predicted better school engagement (p = .006, d = .88). Implications for research and practice are discussed.