Comparative analysis of the transition from higher education to work often focuses on cross-national variations of higher education systems to explain country-specific mobility patterns of higher education graduates. The structure of graduate labour markets, however, has received less attention, despite differences across countries. Variations in the structure of public services and the professions are particularly pronounced. This article, therefore, analyses graduate employment patterns in professional and public sector jobs. It develops an explanatory framework based on the concept of internal labour markets and asks whether country-specific degrees of "social closure" in the public and professional sector influence individual transitions from higher education to work. To answer this question, the study looks at two countries that vary strongly in their institutional organisation of public and professional services--namely, Britain and Germany. Empirically, the transition to public and professional sector employment is studied, as well as between-sector career mobility of higher education graduates. Results indicate that public and professional sector employment is more common in Germany, while further career mobility between these sectors is higher in Britain. (Contains 6 notes, 3 tables, and 3 figures.)