The authors document the correlation between the workplace diversity in bureaucratic organizations and public service delivery, in the context of Nigeria, where ethnicity is a salient form of self-identity. This article expands the empirical management literature highlighting beneficial effects of workplace diversity, that has focused on private sector firms operating in high-income settings. The analysis combines two data sources: (i) a survey to over 4,000 bureaucrats eliciting their ethnic identities; (ii) independent engineering assessments of completion rates for 4,700 public sector projects. The ethnic diversity of bureaucracies matters positively: a one standard deviation increase in the ethnic diversity of bureaucrats corresponds to 9 percent higher completion rates. In line with the management literature from private sector firms in high-income countries, this evidence highlights a potentially positive side of ethnic diversity in public sector organizations, in the context of Sub-Saharan Africa.