Adult male albino rats were fed on stored wheat grains (Triticum aestivum L.) treated with malathion and spinosad at both 8 and 16 ppm for 90 consecutive days to evaluate their hepatic and renal toxicity. The activity of serum acetylcholinesterase (AChE) was decreased in rats treated with the higher concentration of both tested pesticides. Biochemical parameters of liver functions [i.e., aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), acid phosphatase (ACP) activity, as well as total protein, albumin, bilirubin and cholesterol levels] were severely affected especially at higher concentration. Malathion and spinosad elevated the activity of ALT, AST, ALP and ACP in rats treated with the higher concentration. Also, total and direct bilirubin levels increased in rats treated with the higher concentration of both pesticides. On the contrary, both pesticides decreased total protein and albumin levels in treated rats in a concentration-dependent manner. Furthermore, malathion was found to be hyperglycemic. Kidney function parameters (i.e., urea and creatinine levels) were increased in treated rats in a concentration-dependent manner. The above mentioned effects were supported by histopathological examination of liver and kidney tissues. The obtained results indicated also that malathion was able to cause a more pronounced hepato- and renal toxicity in rats than spinosad.