Abstract:In addressing the topic of decision making in the water sector, what has been suggested to be useful up to this point is benchmarking. This paper aims at exploring the relationship between the Operating Cost Coverage Index and customer complaints about water and wastewater services for 1898 water utilities in 11 countries, i.e., Australia, Bangladesh, Brazil, Lithuania, Peru, Poland, Russia, Serbia, Tanzania, Zambia, and Zimbabwe. The data used are the most recent available per country through the International Benchmarking Network for Water and Sanitation Utilities (2013)(2014)(2015)(2016). In order to examine the aforementioned relationship and further reveal the key policy messages that are derived by this analysis, parametric and non-parametric group comparisons are employed. The results of those comparisons concerning the two examined indicators of this study consist of two main findings: The first sheds light on the rational argument that well performing utilities open their data to others-at least more so than those not performing as well. The second is that there could be an association between financial performance and the complaints received about water and wastewater services, but this finding requires further investigation.