We describe a public good experiment, a type of economic experiment commonly used to examine feelings of prosocialitythat is, behaviour which is positive, helpful and intended to promote social acceptance and friendshipand community cohesion, carried out in Rwanda. Contributions in different parts of the country are affected by the local intensity of the 1994 genocide, with more generous contributions being made in areas where violence was greater. This supports earlier research indicating that conflict experience leads to greater prosociality. However, we also find that people who have not, themselves, been targets of violence give lower contributions than people who have. The considerable group-related and regional differences in social behaviour may have implications for the country's policies to deal with social cohesion.