OBJECTIVES: Affective response during physical activity can partly determine its adherence in adults with severe obesity living or not with a mental disorder. This study examined affective responses to physical activity in adults with severe obesity living or not with a mental disorder. MATERIALS AND METHODS: Two groups (24 adults with severe obesity, body mass index=44.4kg/m RESULTS: No between-group effect in the distance walked was found. Results showed a significant time effect indicating a decline in pleasure over time in both groups from the first to the second 6-min walking exercise No interaction effects were detected in both 6-min walking exercise. DISCUSSION: Affective responses similarly declined in both groups indicating that obesity, rather than the presence of a mental disorder, is partly responsible for this decline.