A sample of one hundred and sixty-eight New South Wales local government libraries is used to analyse the efficiency measures derived from the non-parametric technique of data envelopment analysis. Depending upon the assumptions employed, 9.5 per cent of local governments were judged to be overall technically efficient in the provision of library services, 47.6 per cent as pure technically efficient, and 10.1 per cent as scale efficient. The study also analyses the posited linkages between comparative performance indicators, productive performance and non-discretionary environmental factors under these different model formulations. The results indicate that the presence of exogenous factors and scale effects account for a major portion of the differences in observed efficiency between different groups of local governments.