In 2007, the rate of intestinal helminth infection in primary school-aged children in a rural village in Southwestern Kenya was estimated to be at least 68%, based on direct stool smear. Since the 2007 survey, these same school children have been treated with 400-mg albendazole every 3 months. We repeated a cross-sectional stool survey in the same area in 2010 (i.e. 3 years later) to estimate the current parasite prevalence. While only 44.5% of children were infected in 2010, the decline was not as marked as one might expect from a well-managed quarterly deworming campaign. Due to the relative insensitivity of the technique utilized here-the direct smear examination of a single stool sample-we were only able to identify heavy infections, and the true rate of parasitism is likely much higher, suggesting heavy environmental contamination and rapid re-infection rates. Community education and sanitation improvements are needed for more definitive impact.