Couple cooperation is hypothesized to be essential in the resolution of interpersonal marital problems. Data from a sample of newlywed couples support this hypothesis as well as the validity of our measure of cooperation. We then test a model stipulating marital satisfaction and trust as antecedent conditions leading to cooperative problem solving for each of three time periods, using structural equation modeling methods. We also test the overall fit and lagged effects of the model combining all three periods. Finally, we examine how the amount and distribution of 10 resources influenced how the model functioned. By waves 2 and 3, education, liking, and a combined measure of interpersonal skills all showed significant effects on the model. We discuss the relevance of the findings for a theory of marital problem solving and consider the significance of studying newlyweds. (Contains 4 figures, 2 tables, and 13 footnotes.)