SUMMARYWe examined charitable giving in Japanese public sector workers during an emergency, such as a natural disaster. We used pooled data from before and after the Great East Japan Earthquake in March 2011, which amounted to approximately 3,400 observations over two years. Our empirical analysis found that, similar to other workers, public sector workers’ turnout in response to disaster‐related causes was higher during the post‐disaster emergency period than in ordinary times; however, their contribution amounts were lower. This contrast casts doubt on the assumption that public sector workers are always inherently more prosocial than other workers. In our case study, anticipation of and uncertainty about the possible future reduction of their disposable income to finance post‐disaster reconstruction may have prompted their conservative prosocial response.