Objective: To follow distressed married couples for 5 years after their participation in a randomized clinical trial. Method: A total of 134 chronically and seriously distressed married couples were randomly assigned to approximately 8 months of either traditional behavioral couple therapy (TBCT; Jacobson & Margolin, 1979) or integrative behavioral couple therapy (IBCT; Jacobson & Christensen, 1998). Marital status and satisfaction were assessed approximately every 3 months during treatment and every 6 months for 5 years after treatment. Results: Pre- to posttreatment effect sizes on marital satisfaction were d = 0.90 for IBCT and d = 0.71 for TBCT, which were not significantly different. However, data through 2-year follow-ups revealed statistically significant superiority of IBCT over TBCT in relationship satisfaction, but subsequent data showed increasing similarity and nonsignificant differences in outcome. At 5-year follow-up for marital satisfaction relative to pretreatment, effect sizes were d = 1.03 for IBCT and d = 0.92 for TBCT; 50.0% of IBCT couples and 45.9% of TBCT couples showed clinically significant improvement. Relationship status, obtained on all 134 couples, revealed that 25.7% of IBCT couples and 27.9% of TBCT couples were separated or divorced. These follow-up data compared favorably to other, long-term results of couple therapy. Conclusion: TBCT and IBCT both produced substantial effect sizes in even seriously and chronically distressed couples. IBCT produced significantly but not dramatically superior outcomes through the first 2 years after treatment termination but without further intervention; outcomes for the 2 treatments converged over longer follow-up periods. (Contains 3 tables, 2 figures and 6 footnotes.)