An emerging literature on rebel groups’ restraint in the use of sexual violence has begun to explore the role of the commander. This study seeks to build on this literature by investigating under what conditions rebel commanders will enforce restraint. I argue that perpetrating sexual violence against civilian communities to which a rebel group has ethnic ties is highly costly for the rebel commander. Thus, commanders will strive to enforce restraint in the use of sexual violence against co-ethnic civilians. However, their ability to enforce restraint, I argue, hinges on the authority and influence they have over their combatants. Hence, I hypothesize that rebel groups with strong commanders are more likely to enforce restraint toward co-ethnic civilians. This argument is examined through unique spatial data on the geographic patterns of rebel sexual violence combined with spatial data on rebel groups’ co-ethnic civilian populations in Africa 1989-2009. Regression analysis finds that rebel groups with strong commanders and ethnic ties are less likely to perpetrate sexual violence against co-ethnics, yet also that groups with weak commanders are more likely to victimize co-ethnics.