OBJECTIVE. We examined agreement of data between self-reported and objectively assessed exercise adherence among women with systemic lupus erythematosus. METHOD. Eleven participants completed weekly exercise logs on date and duration of exercise during a 10-wk Wii Fit™home-based program. Afterward, exercise data from the log were compared with those recorded in the Wii console. RESULTS. Of the paired data, the mean duration of exercise recorded in the Wii was 29.5 min and that recorded in the log was 33.3 min. The composite intraclass correlation for exercise duration between exercise log and the Wii Fit was 0.4. The 95% limits of agreement indicated large between-subjects variability. CONCLUSION. Exercise logs exhibit a marginally acceptable agreement with Wii estimation of exercise duration at a group level. However, caution should be applied when using the exercise log as a measure of a person's exercise behavior because of the tendency to overreport.