Individual variability in response to behavioral weight loss programs remains an unresolved and perplexing issue for health psychologists. Determining in advance who will succeed or fail at losing weight would be useful in devising programs that produce a more homogeneous and dramatic response to treatment. In order to examine which responses to an application and a relationship questionnaire relate to weight loss success, 23 couples participated in a 1-year correspondence weight reduction program. One person in each couple enrolled to lose weight and the other agreed to act as helper. Reducers completed an application form recording demographic information, reactions to past attempts at weight loss, and number of previous methods used. Helpers rated their willingness to perform weight-related tasks to help the reducer. Both reducers and helpers completed the Locke-Wallace Marital Adjustment Scale. Analyses of results indicated that better educated reducers and helpers with fewer negative attitudes about past weight loss attempts and fewer prior attempts at losing weight performed better, and that those with partners less willing to aid them or with unsatisfying marital relationships lost the most weight. The findings suggest that the application items and the measure of relationship satisfaction may be useful predictors of weight loss. (PAS)