To evaluate the potential transmission of Schistosoma mansoni through well water pumped into households in a rural Brazilian community within the context of Brazil's rural electrification program Luz Para Todos (Light for All). All households were interviewed about their water facilities and domestic water use, all household members were examined for S. mansoni infections and positives treated, and malacological and water contact studies were performed between 2001 and 2009. Thirty-one of the 142 households in the Virgem das Graças study area owned wells with electric pumps in 2009, vs. no wells in 2001, and the number of water storage tanks increased from 85 to 131. The potential for schistosomiasis transmission through piped well water was indicated by the recovery of Biomphalaria gabrata, including S. mansoni-infected snails, from wells, the presence of Biomphalaria in tanks and the ability of S. mansoni cercariae to remain infective for considerable distances in flowing water. However, access to well water was not associated with higher S. mansoni infection rates. Our results indicate that further studies are needed to determine the infectivity of well water and its impact on schistosomiasis transmission. © 2012 Blackwell Publishing Ltd.