We investigate the interaction of pro-social motivation and wages in pro-social organizations with a novel subject pool, 1700 students destined for the private and public sectors in Indonesia, using a measure of pro-social motivation that exactly matches the mission of the organization. Three novel conclusions emerge. Consistent with a common, but untested, assumption in the theoretical literature, workers with greater pro-social motivation exert higher real effort. However, high pay attracts less pro-socially motivated individuals. Furthermore, we also test whether a real world pro-social organization (the Indonesian Ministry of Finance) attracts pro-socially motivated workers. We find that prospective entrants into the Indonesian Ministry of Finance exhibit higher levels of pro-social motivation than a comparable sample of general workers.