This study investigated the individual experience of flow and its relations with emotions and the perceived socio-cognitive processes involved in a computer-supported collaborative problem-solving task. Participants were asked to play in dyads the video game Portal 2 ® and then to individually complete three subjective questionnaires (emotion, collaboration and flow). Results showed that flow is related to both the modelling of the partner's emotions and the perceived mutual engagement in collaborative processes such as information pooling and transactivity. They support the idea that the flow experience should be considered as a means to improve the quality of computer-supported collaborative learning.