Comparative scholars emphasise that public administration should be understood in terms of context-bound patterns of organising and decision-making. Agencies in the same context will display more commonalities than those in another. At the same time, there is good empirical evidence for organisational-level variation in decision-making. For instance, not all agencies in one country are delegated similar levels of personnel management autonomy. This article develops a theoretical argument about how administrative tradition moderates the effect of organisational drivers of personnel management autonomy. We identify the degree of uniformity embedded in administrative tradition as a key explanatory factor for this relationship. In empirical terms, the article compares the perceived personnel management autonomy of agencies in 10 European countries nested in three country clusters (Scandinavian, Latin-Napoleonic and Continental). The analysis confirms theoretical expectations about the context-specific effects of organisational characteristics on personnel management autonomy in agencies.