We investigate differences in prosocial motivation in the public and private sector. To overcome identification difficulties we focus on retired workers using data from the Survey on Health, Ageing and Retirement in Europe (SHARE), consisting of 20,000 retired workers from 12 countries. Our measure of prosociality is incidence of voluntary work while retired, which arguably captures genuine prosocial preferences. We find that public sector retirees are significantly more likely to volunteer. However, after controlling for a rich set of demographic and economic characteristics the gap disappears. Our results indicate that the composition of the public sector workforce (highly educated, white collar jobs) accounts for the different prosocial attitudes of workers in the two sectors, while we do not find evidence of prosocial motivation that is specific to the public sector.