The principal objective of this paper is to compare countries’ performance in the water and sanitation sector and analyze how effectively they used the development aid received for the Water and Sanitation sector (WSS). The paper uses a standardised measurement framework known as-the Watsan Index of Development Effectiveness (WIDE) - which compares drivers of progress with results achieved, and ranks African countries by the level of outcome obtained per unit of available input. Results are corroborated by econometric analysis and case studies.