Objective: We identify complexities encountered, including unanticipated crossover between trial arms and inadequate “standard of care” violence services, during a cluster randomized trial (CRT) of a community-level intimate partner violence (IPV) and HIV prevention intervention in Uganda. Method: Concepts in public health ethics—beneficence, social value of research, fairness, standard of care, and researcher responsibilities for posttrial benefits—are used to critically reflect on lessons learned and guide discussion on practical and ethical challenges of violence intervention CRTs. Results: Existing ethical guidelines provide incomplete guidance for responding to unexpected crossover in CRTs providing IPV services. We struggled to balance duty of care with upholding trial integrity, and identifying and providing appropriate standard of care. While we ultimately offered short-term IPV services to controls, we faced additional challenges related to sustaining services beyond the “short-term” and posttrial. Conclusion: Studies evaluating community-level violence interventions, including those combined with HIV reduction strategies, are limited yet critical for developing evidence-based approaches for effectively preventing IPV. Although CRTs are a promising design, further guidance is needed to implement trials that avoid introducing tensions between validity of findings, researchers’ responsibilities to protect participants, and equitable distribution of CRT benefits. (PsycINFO Database Record (c) 2016 APA, all rights reserved)