The difficulties in measuring maternal mortality have led to a shift in emphasis from indicators of health to indicators of use of health care services. Furthermore, the recognition that some women need specialist obstetric care to prevent maternal death has led to the search for indicators measuring the met need for obstetric care. Although intuitively appealing, the conceptualization and definition of the need for obstetric care is far from straightforward, and there is relatively little experience so far in the use and interpretation of indicators of service use or need for obstetric care. In this paper we review indicators of service use and need for obstetric care, and briefly discuss data collection issues.