Destruction rates of parasite eggs in stored sludge were examined to help understand the fate of these agents of enteric diseases in sludge lagoons. Eggs from the roundworms, Ascaris, Toxocara, and Trichuris, and the tapeworms, Hymenolepis, were treated with domestic sludges by aerobic or anaerobic processes. Although storage temperature was found to be the most important factor affecting the destruction and viability of these eggs, other factors, such as the type of sludge digestion, whether or not the eggs were digested along with the sludge or added later, stored in the soil vs. sludge, pH, and egg species also exhibited some minor effects. These controlled laboratory studies suggest that lagooning of sludge can be an effective method for the elimination of parasite eggs, particularly in warmer geographic locations.