This article examines the institutional politics of law enforcement in Nigeria by focusing on illegal drug control since the mid 1980s. It assesses the available academic research on law enforcement governance, and contrasts it with an in-depth case study of drug law enforcement. The case study confirms views of the politicised nature of law enforcement. However, it goes beyond the patron-client centred approach to politics prevalent in the literature on African policing. The article adds an institutional dimension to the study of law enforcement governance, highlighting processes of centralisation, exclusion and shifting bureaucratic interests that have been central to the development of Nigerian drug law enforcement. It is based on previously inaccessible data from inside Nigerian drug law enforcement.