The water and sanitation sector in the Metropolitan Region of Santiago de Chile (MRS) is mainly privately owned or operated. The sector prides itself on having a modern and effective regulatory framework. Nevertheless there are still sustainability deficits existing as far as governance structures and integrated water resource management are concerned. This paper analyzes the sustainability performance of the sector by using integrated sustainability indicators. The research focuses on institutional and governance aspects and the ecological, economic and social impacts of the newly privatized water and sanitation sector. Detected sustainability deficits, conclusions and possibilities for actions are presented.