Attracting household savings and private sector investments will speed up WASH coverage and can be considered to be one of the most cost effective public health interventions. Microfinance can play a catalytic role in increasing the uptake of WASH improvements by poor households. But WASH financing differs from the generic income generating loan (IGL) product significantly, and there are several other strategic issues that determine the suitability for rolling out WASH finance. MFIs have to consider these issues carefully before embarking on a WASH product development exercise. In this Note we explore some key strategic issues that determine the potential for a WASH finance portfolio including ecological factors, the public good nature of WASH, usage level of existing WASH infrastructure, capital for WASH financing, collaborations with WASH product/service providers and awareness amongst potential WASH financing customers.