Side effects of tested compoundsi.e., Fenpyroximate, fenarimol ; sulphur and some of their alternatives i.e. mineral oil, Kz-oil and black pepper extract on some enzyme activities in white rats were studied. Results showed that serum ChE activity was significantly decreased in all treatments ,except in fenarimol treament it increased.Total protein concentration in serum was increased in the case of fenarimol, sulphur, black pepper extract and kz-oil . Albumin concentration in serum was not significantly changed with all tested copounds. Serum alkaline phosphatase activity was significantly increased with all tested compounds.The maximum percent of increasing was found in case of fenpyroximate treatment.Serum AST activity decreased with fenpyroximate and sulphur treatments, while it increased in the black pepper extract treatment.Serum ALT activity decreased with fenpyroximate and sulphur, while it was increased with fenarimol and black pepper extract.Creatinine concentration in serum was not significantly changed with all tested compounds.Urea concentration in serum increased with fenarimol and black pepper extract treatments.With the exception of sulphur treatment all tested compounds caused liver damage as pyknosis of karyolysis of the hebatic nuclei, congestion of the protoliver with infiltration of the protal area with lymphocytes, coagulation necrosis of the hepatocates . Fenpyroximate and fenarimol caused increase in the marginal zone of white pulp, but Kz-oil caused decrease in the size of white pulp.All tested compounds caused kidney damage as mild cloudy swelling of the renal epithelium, congestion of glomerular tuft inter tebular, necrosis of glomerular renal epithelium.Brain tissue was not affected in any treatment