Health care institutions worldwide are increasingly the subject of analyses aimed at defining, measuring, and improving organizational efficiency. However, despite the importance of efficiency measurement in health care services, it is only relatively recently that the more advanced econometric and mathematical programming frontier techniques have been applied to hospitals, nursing homes, health management organizations, and physician practices, among others. This article provides a synoptic survey of the comparatively few empirical analyses of frontier efficiency measurement in health care services. Both the measurement of efficiency in a range of health care services and the posited determinants of health care efficiency are examined.