The present study was attempted to determine whether self-efficacy and self-motivation would predict outcome in an intensive weight loss program. The subjects included 52 males and 95 females who were at least fifty pounds overweight (mean age = 43 years). The data were analyzed through multiple regression on three separate dependent variables: actual weight loss, adjusted weight loss and percentage of sessions attended. Outcome was predicted based on the following variables: self-efficacy (as measured by confidence estimates and outcome expectancies) and self-motivation (as measured by the Self-Motivation Inventory). The predictors accounted for 32.2% (p less than .01) of the variance in actual weight loss, 8.5% (p less than .01) of the variance in adjusted weight loss and none of the variance in percentage of sessions attended. Self-motivation did not correlate significantly with either actual or adjusted weight loss, while self-efficacy measures did. However, the correlation of the two self-efficacy measures (r = -.07, p greater than .05) suggests that these variables do not constitute a unitary construct and should be conceptualized as independent predictors. These findings suggest that confidence estimates and outcome expectancies are useful predictors of weight loss.