In Vietnam, achieving sustainableprovision of water services for communities in rural areashas been a challenge for years. About 74 percent of theVietnamese population is concentrated in rural areas, yetjust 48 percent of households have access to clean water,compared with 82 percent in urban areas. Only 30 percent ofsmall towns have piped water systems, and even then theproportion of connected households can be as low as 20percent. Many settlements have no water systems, and duringthe dry season residents have to rely on polluted sourcesfor basic household needs. This paper reviews the successfulimplementation and subsequent scale-up of an Output-BasedAid (OBA) scheme to provide access to safe, clean water forlow-income, rural households in central and southernVietnam, through local communities and small private operators.