The sanitation sector plays a key role in human life. Efficient management of water resources is completely revelant to society because of their economic and productive importance for the development of other goods and services. This study presents a benchmarking analysis in order to evaluate the efficiency of the operating costs of sanitation companies in Brazil. Three benchmarking methodologies were used, Data Envelopment Analysis (DEA), Corrected Ordinary Least Square (COLS) and Performance Indicators Analysis. Initially an average efficiency was estimated from the DEA and COLS. Later, through TOBIT regression, an adjustment of this efficiency was made through this uncontrollable variables by companies. Finally, an additional analysis was performed using 15 performance indicators that spanned average cost characteristics, productivity and water losses in the sanitation sector. The data used for this study were provided by the Brazilian Sanitation Information System (SNIS). To estimate the efficiency was considered as an input variable operating costs of companies (OPEX).Regards to product, the amount of variable active links and volume of billed water and sewage were considered. It was observed the impact of uncontrollable variables benefited performance of the companies, but did not cause significant changes on the position in the ranking of efficiency. The result of the average efficiency estimated by the DEA and COLS methodologies indicated SANEPAR as a benchmark due to its operating costs, as well as the performance indicator analysis for the year 2012.