Galega officinalis L. (Papilionaceae) is widely used in folk medicine as antidiabetic or for increasing lactation. There is a little information about its possible toxicity. In this study, acute and subchronic toxicity of aerial parts of Galega officinalis in Wistar rats have been evaluated. For the acute toxicity study, the animals received orally four different single dose of plant suspension and were kept under observation for 14 days. The results indicated that LD50 of Galega officinalis is higher than 5 g/kg. In the subchronic study, 48 rats were divided into four groups and were fed a diet containing 0%, 0.15%, 1.5% and 3% (w/w) of Galega officinalis. After 90 days blood and tissue samples were taken for hematological, biochemical and histopathological determinations. An increase in serum levels of cholesterol, creatine phosphokinase, lactate dehydrogenase and total and conjugated bilirubin was observed. Some parameters such as calcium, albumin, albumin/globulin ratio, hematocrit, WBC and platelet counts were decreased. In microscopic examination, sinusoidal congestion in liver and alveolar hemorrhage was observed. Other parameters showed non-significant difference between treatment and control groups. Present data suggest that liver and lung could serve as target organs in oral toxicity of this plant.