The attributes of couples planning to marry can affect their future relationship satisfaction. To study this phenomenon, a social exchange model was applied to a sample of couples planning to marry to assess the predictive validity of a measure of positive exchange. The longitudinal design of the two-and-a-half year investigation provided direct information about the development of marital distress which was unavailable from previous cross-sectional studies. Study results indicated that the more positively couples rated their early interactions, the higher their relationship satisfaction was likely to be at the final followup. The social exchange model proved to be a useful model for understanding the development of marital problems, but limitations regarding its testability must be recognized and rectified. The implications of the study for the marital interactions are discussed, as well as implications for developing programs designed to prevent marital distress. (Author/PRK)