The hepatotoxic and hematologic effects of the extract of a Nigerian herbal remedy, U&D Sweet Bitter, were investigated in mature Wistar albino rats. Twenty male albino rats were allocated into four dose groups of five rats each. Food and fluid intake, body weight, absolute and relative weight of the liver, and hematologic and biochemical parameters were measured. The absolute and relative weights of the liver significantly decreased (p < or = .05) when compared with controls. Doses of 539, 1077, or 1616 mg/kg of U&D Sweet Bitter given orally for 90 d induced a significant (p < .05) dose-dependent increase in aspartate aminotransferase and alkaline phosphatase and decrease in alanine aminotransferase compared with controls. Hepatic and haematologic parameters of treated groups were significantly different from those of controls. Histologic examination revealed that U&D Sweet Bitter induced severe necrosis and edema.