Erythritol was orally administered to Wistar rats at dietary levels of 0, 5, and 10% for 4 weeks. Soft stools and diarrhea were observed in male and female animals of the 10% group and in female animals of the 5% group. These symptoms disappeared during the course of the study. Mean body weights of male rats in the high-dose group were significantly lower than those of controls during the course of the study. No such differences were observed in females. Small statistically significant changes in certain hematological, clinical chemistry, and urine parameters were noted in the high-dose group but were judged not to be biologically important. Weights of the cecum were increased relative to those of the controls. No treatment-related histological changes were observed. No ill effects, other than early diarrhea, were observed from erythritol levels at 5 or 10% in the diet. Based on these results, it was concluded that the feeding of erythritol at a dietary level of 10% did not result in toxicologically significant effects.