This study evaluated the responsiveness of the Canadian Occupational Performance Measure (COPM), an individualized, client-centered outcome measure for the identification and evaluation of self-perceived occupational performance problems. We recruited 152 consecutive patients with various diagnoses, admitted to the outpatient clinic of two occupational therapy departments, to complete a COPM interview and three self-reported health status questionnaires on two occasions: prior to the start of occupational therapy treatment and 3 months later. The three questionnaires were the Sickness Impact Profile (SIP68), the Disability and Impact Profile (DIP), and the Impact on Participation and Autonomy (IPA). We assessed criterion responsiveness by calculating the area under the curve (AUC) for the receiver operating characteristic curve and the optimal cutoff values for the COPM scores.To determine construct responsiveness, we calculated correlations between the change in COPM scores and the change in the SIP68, DIP, and IPA scores. The AUC ranged from 0.79 to 0.85, and the optimal cut-off values for the performance scores and satisfaction scores ranged from 0.9 to 1.9.We found significant positive correlations between the COPM scores and the SIP68, DIP, and IPA scores. The capability of the COPM to detect changes in perceived occupational performance issues is supported.