Excerpt from Report Abstract: The present study evaluated the effects of mothers’ participation in an eight week intervention program, Understanding Dad™, on mothers’ relationship awareness, knowledge of healthy co-parenting relationships, and relationship self-efficacy. Thirty-four mothers were recruited from four sites to participate in a study that used a pretest/post-test one-group design. Over the course of this eight week program, mothers demonstrated moderate to large gains in each of the outcome measures, after controlling for mothers’ educational level. Moreover, there was one significant within-subjects interaction effect for time x location. That is, mothers made significantly greater gains in pro-relationship knowledge in one of the intervention sites. Implications for future research are discussed.