The embryotoxicity/teratogenicity of the natural sweetener isomaltulose (Palatinose) was studied in Wistar rats. Groups of 24 mated females were fed diets containing isomaltulose at levels of 0, 2.5, 5 and 10% from day 0 to day 21 of pregnancy. The dams were killed on day 21 of pregnancy. No maternal toxicity occurred and no effects on reproductive performance, nor on embryonic or foetal development, including visceral and skeletal examination, were seen in any of the groups fed isomaltulose. The dietary level of 10% isomaltulose was equivalent to about 7 g/kg body weight/day.