Professional services matter for development in East Africa. Business services, including professional services, are among the most dynamic services sectors; and are a key input for other sectors. Greater use of professional services by East African firms is associated with higher labor productivity. But there is a large gap between the potential contribution these services could make and the meager contribution they make today. National markets for professionals and professional services in East Africa remain underdeveloped, whereas regional markets are fragmented by restrictive policies and regulatory heterogeneity. An effective reform agenda will require policy action in four areas: education, regulation of professional services, trade policy, and labor mobility at both the national and international levels.