There is increasing realization that state capacity is a fundamental ingredient for effective governance, and is a crucial element of long-run economic development. This paper offers an overview of the strengths and limitations in current empirical research on the measurement of state capacity. The paper also surveys the fast emerging literature on the determinants and effects of state capacity. We argue that existing measures on governance quality used in cross-national research can be usefully exploited to capture different aspects of state capacity, and show that post the end of the Cold War, developing economies have experienced improvements in legal, administrative and bureaucratic capacity, but the gap with advanced economies is still wide. Future research should address the short temporal coverage of available measures of state capacity, as well as providing a systematic quantitative assessment of the determinants of capacity and of its effects on development outcomes, such as health and education, which have not received sufficient scrutiny.