An end-of-season party held at a camp for private residential school led to 50 cases of Giardia lamblia. The back-to-school get-together provided fresh fruit and vegetables from the camp garden; these were assessed to be the likely source of the outbreak. The garden was not fenced off, and the camp's goats were free to enter it, as were other animals. Goat manure tested positive for G. lamblia. The goats may not have been the sole source of the outbreak. Children had washed vegetables and fruits in the creek prior to eating them. Giardia lamblia infections are most often associated with consumption of contaminated water.