BACKGROUND AND AIMS: Sexual violence (SV) is common during conflict. Despite reports of rape-related incidents of HIV infection, ecological analyses have found no association between SV and HIV at a population level. This has led to debate in the humanitarian, security and public health arenas about whether SV is an important HIV risk factor in conflict-affected settings. This paper uses published evidence on sexual violence in Africa and modelling to explore when SV may increase individual HIV risk and community HIV incidence. METHODS: Publications on sexual violence in conflict settings were reviewed and a mathematical model describing the probability of HIV acquisition was adapted to include the potential effect of genital injury and used to estimate the relative risk of HIV acquisition in 'conflict' versus 'non-conflict' situations. An analytical equation was developed to estimate the impact of SV on HIV incidence. RESULTS: A rape survivor's individual HIV risk is determined by potentially compounding effects of genital injury, penetration by multiple perpetrators and the increased likelihood that SV perpetrators are HIV infected. Modelling analysis suggests risk ratios of between 2.4 and 27.1 for the scenarios considered. SV could increase HIV incidence by 10% if rape is widespread (>40%); genital injury increases HIV transmission (threefold or more); at least 10% of perpetrators are HIV infected and underlying HIV incidence is low (<0.5%). CONCLUSION: The analysis illustrates that SV is likely to be an important HIV risk factor in some conflict-affected settings. More generally, it indicates the limitations of using broad aggregate analysis to derive epidemiological conclusions. Conflict-related initiatives offer important opportunities to assist survivors and prevent future abuses through collaborative programming on reconstruction, HIV and sexual violence.