Objective: Although self-efficacy has received increasing attention for its role in weight loss, there is less research examining this relationship in minority samples. The purpose of this study was to determine whether self-efficacy for weight loss was predictive of weight change in a sample of African-American women. Research Methods and Procedures: Subjects were 106 overweight or obese, low-income African-American women participating in a weight management intervention that involved either personalized monthly sessions with their primary care physician or standard care. Weight and self-efficacy for weight loss were assessed at baseline and at the end of the 6-month treatment. Results: For subjects in the personalized intervention, baseline self-efficacy was predictive of subsequent weight change, such that higher levels of self-efficacy before treatment were associated with less weight loss. In contrast, improvements in self-efficacy during treatment were associated with greater weight loss for the personalized intervention group. Discussion: Results suggest high self-efficacy for weight loss before treatment may be detrimental to success, whereas treatments that improve participants' self-efficacy may result in greater weight loss. High pretreatment self-efficacy may be indicative of overconfidence or lack of experience with the difficulties associated with weight loss efforts. Whereas replication is needed, our results suggest that self-efficacy is an important variable to consider when implementing weight loss interventions. Copyright & 2004 NAASO.