Purpose <p>This study evaluated the efficacy of an online intervention targeting intimate partner violence (IPV) in perinatal women, <i>S</i>trength for <i>U</i> in <i>R</i>elationship <i>E</i>mpowerment (SURE), relative to an attention, time, and information-matched control, on IPV severity, positive affect and well-being, and perceived emotional support across a 12-month follow-up.</p> Methods <p>Perinatal women (<i>N</i> = 122) who reported past 12-month IPV and recently engaged in mental health treatment were randomized to SURE (<i>n</i> = 65) or control (<i>n</i> = 57). SURE participants received a 40-minute online intervention based in motivational interviewing and empowerment. Control participants viewed a 40-minute online video of popular entertainment, followed by questions about preferences. Both conditions also included a brief 10-15-minute telephone-delivered booster session one month after the online session. Follow-up assessments occurred at 6 weeks, and 3-, 6-, and 12-months since the baseline visit.</p> Results <p>Both interventions exhibited a significant drop in IPV severity from baseline to 12-month follow-up, with no significant differences between arms (range of standardized effect sizes for the time by group interaction <i>=</i> 0.20–1.65). Significant intervention effects were found for both positive affect and well-being (range of standardized effect sizes for the time by group interaction = -0.04-1.62) and perceived emotional support (range of standardized effect sizes for the time by group interaction = 0.65–2.10), where participants in SURE exhibited significant increases in both outcomes, while control participants did not.</p> Conclusion <p>Results suggest that SURE provides a good model for an online intervention for perinatal women who have sought mental health services.</p>