Lobeira (Solanum lycocarpum) is a Brazilian plant used as a hypoglycemic agent. In this study, the toxic effects of lobeira were evaluated during the fetogenesis period. Twenty pregnant Wistar rats were randomly allocated into two groups: control and treated, which received, via oral gavage, 0.5 ml of distilled water or 100 mg of the lobeira powder/kg of body weight, respectively, during days 17-20 of pregnancy. Maternal toxicity was evaluated by body weight, food intake, piloerection, locomotor activity, diarrhoea and vaginal bleeding. Euthanasia was done on 21st day, when ovaries, fetuses and their respective placentas were removed. Resorptions, live and dead fetuses were recorded. External malformations and fetal body, brain, liver, lung and kidneys were also weighed. No clinical signs of maternal toxicity were observed. The placenta weights of the treated rats were lower than those of the control (P<0.01). Lungs (P<0.01) and kidneys (P<0.02) of the fetuses treated with lobeira were also significantly reduced, suggesting a fetotoxic effect of this plant.