Prolonged oral administration (90 days) of larvin 50 DF to albino rats in doses 1/20 and 1/10 LD50 (19.91) and 39.80mg/kg b. wt.) resulted in a significant increase in Alanine aminotransferase (ALT). Aspartate aminotransferase (AST) and alanine phosphatase activities. Urea and creatinine concentrations were also significantly increased in treated rats as compared with those of control. Total lipids and cholesterol were Significantly decreased. Histopathological examination showed degenerative changes and necrosis in liver, kidney, cardiac muscles, cerebrum and cerebellum. No hematological changes were observed.