Clean water is essential for human survival. Yet, many people do not have access to clean water in Vietnam. Only around 23% of the population had access to piped water in 2006. This study measures the effect of piped water on household welfare using difference-in-differences estimators and panel data from the Vietnam Household Living Standard Surveys. Findings show that the effect of piped water on household income and labor supply is positive but small and not statistically significant. The effect of piped water on sickness of household members is negative but not statistically significant.