Individual-oriented relationship education aims to support healthy relationship development for singles, and provides flexibility for couples when only one member is available or willing to attend. While quasi-experimental studies have shown some benefits for those who attended relationship education individually, no randomized controlled trials have been conducted for individual-oriented RE. Moreover, it is not clear how relationship education benefits the co-parenting relationship when only one parent attends. Thus, this paper presents the results of a randomized controlled trial, with a wait-list control group, for a sub-sample of parents (N = 322) who participated in a 6-month trial of individual-oriented relationship education utilizing Prevention and Relationship Education Program's (PREP) Within My Reach (WMR) curriculum. Results indicated statistically significant, small, positive intervention effects on parent-child relationships 3 months after random assignment. However, no other treatment effects were detected for parents. We also found no statistically significant differences in the rate of change over the 6-month study period between treatment and wait-list control parents. There was a statistically significant effect for time, indicating that all enrolled parents in the study reported significant positive growth on emotion regulation, positive encouragement, parent-child relationships, and parental adjustment. We discuss implications for relationship education programming, as well as evaluating outcomes in future studies.