The paper measures the technical efficiency in the health care industry. Our aim is twofold: on one side we have a methodological goal, while on the other we want to apply different methodologies developed to measure technical efficiency to a set of empirical data; moreover, we want to explain different efficiency levels of hospitals located in Lombardia. After proposing a brief review of the most important measures (Debreu-Farrell, Shepard’s distance function) and methodologies (dea, stochastic frontiers) in the measurement of technical efficiency, we survey the recent empirical literature on efficiency assessment in the health care sector. We then apply efficiency estimation techniques to a cross-section of public and private hospitals in Lombardia. Our results show that dea efficiency scores are not robust to different model specifications; moreover, efficiency measures obtained with dea and with the alternative stochastic frontier approach show high levels of correlation only when input and output are defined in the same way. Second stage results are more controversial. There seems to be a direct relationship between technical efficiency and firms’ dimensions. Moreover, we found no evidence to support the hypothesis of structural differences in efficiency between nonprofit private hospitals and public hospitals.