Civil society organizations (CSOs) have significantly impacted on the politics of health research and the field of bioethics. In the globalHIVepidemic,CSOs have served a pivotal stakeholder role. The dire need for development of new prevention technologies has raised critical challenges for the ethical engagement of community stakeholders inHIVresearch. This study explored the perspectives ofCSOrepresentatives involved inHIVprevention trials (HPTs) on the impact of premature trial closures on stakeholder engagement. Fourteen respondents fromSouthAfrican and internationalCSOs representing activist and advocacy groups, community mobilisation initiatives, (...) and human and legal rights groups were purposively sampled based on involvement inHPTs. Interviews were conducted fromFebruary‐May 2010. Descriptive analysis was undertaken across interviews and key themes were developed inductively.CSOrepresentatives largely described positive outcomes of recent microbicide andHIVvaccine trial terminations, particularly inSouthAfrica, which they attributed to improvements in stakeholder engagement. Ongoing challenges to community engagement included the need for principled justifications for selective stakeholder engagement at strategic time‐points, as well as the need for legitimate alternatives toCABs as mechanisms for engagement. Key issues forCSOs in relation to research were also raised. (shrink)