Several recent studies suggest that daily weighing is important for long-term weight control, but concerns have been raised about possible adverse psychological effects. The "STOP Regain" clinical trial provides a unique opportunity to examine this issue both cross-sectionally and prospectively. Successful weight losers (N = 314) were randomly assigned to a control or to a face-to-face or Internet intervention designed to help them maintain their weight loss and were then followed for 18 months. The intervention groups reported increases in daily self-weighing, which were associated with successful weight loss maintenance. We found no evidence that increases in frequency of weighing or daily weighing per se had any adverse effects in this study population. Rather, increases in self-weighing were associated with increases in dietary restraint (p < .001), decreases in disinhibition (p < .003), and decreases in depressive symptoms (p < .002). Moreover, those who weighed daily at 18 months were less likely to report having >or=4 binge episodes per month (p = .03). Daily weighing appears to be an important aspect of weight loss maintenance and was not associated with adverse psychological effects.