We explored the relationship between adolescents' activity-based achievement emotions and their performance during collaborative problem solving (CPS) tasks, which was operationalized as having objective social and cognitive performance dimensions. Participants were 100 adolescent dyads (n = 200) who completed a series of five computer-based CPS tasks while their activity emotions of enjoyment, boredom, and anger were recorded. It was hypothesized, using a partially mediated structural regression model, that individual differences in students' activity emotions would be linked to effort regulation, which in turn, would be associated with both CPS social and cognitive performance. On the basis that more effective collaboration efforts enable better cognitive performance, we also expected CPS social performance to influence CPS cognitive performance. Our hypothesized model fit the data well. All emotions were associated with effort regulation, and effort regulation influenced cognitive performance but showed a weak association with social performance. Instead, anger and enjoyment affected CPS social performance directly. Our findings provide valuable insight into the role of affective experiences in the growing area of measuring 21st century skills in educational settings.