Water and sanitation improvements together with hygiene (WASH) are central to health. However, progress in ensuring access to these basic services remains inadequate, particularly in the rural developing world. To remedy this appalling situation, decision-makers need reliable data on which to base planning, targeting and prioritization. However, the challenges of collecting such data and producing consistent evidence are diverse. To influence policy, data have to be easily and meaningfully interpreted. In addition, the evaluation framework needs to capture the complexity inherent in the delivery of rural services. And with limited resources, the neediest must be prioritized. In this paper we compare three different monitoring and evaluation approaches: health impact indicators, standard indicators of the World Health Organization (WHO)/United Nations Children's Fund (UNICEF) Joint Monitoring Programme (JMP), and one multidimensional, WASH-focused indicator. From a policy-making perspective, the likely utility of the outcomes produced by each approach is discussed. The epidemiological study produces misleading results, which do not help draw relevant conclusions. JMP indicators provide reasonable quality basic estimates of coverage across different contexts, but are inappropriate to build up a complete picture of such context. The index approach takes into account a broader view of service level, and proves useful as a policy tool to guide action towards improved service delivery.