This article examines the impacts of Building Strong Families, a healthy marriage and relationship skills education program serving unmarried parents who were expecting or had recently had a baby. Based on a random assignment research design, the analysis uses survey data from more than 4,700 couples across eight research sites to estimate program effects. Results varied across sites, with one site having a pattern of positive effects (but no effect on marriage) and another having numerous negative effects. However, when impacts are averaged across all research sites, the findings indicate that the program had no overall effects on couples' relationship quality or the likelihood that they remained together or got married. (Contains 5 footnotes, 12 tables, and 1 figure.)