International surveys show that trust in the police varies substantially between countries. This study investigates the underlying causes of this variation, and in particular the effect of perceived corruption in the public sector. A regression analysis of 50 countries worldwide suggests that both perceived corruption in the public sector and trust in government are important predictors of trust in the police. The homicide rate is also statistically significant but seems to have a more modest effect on trust. The findings are compatible with previous research findings that procedural concerns trump outcomes in explaining trust. Moreover, a correlation analysis suggests that perceived corruption in the public sector is more damaging to trust in the police than to trust in other government institutions. A plausible explanation for this is that many consider the police to be an indispensable institution for social order, and corruption is antithetical to this mission.