Thiamethoxam is a synthetic organic insecticide belong to The most significant new class of pesticides created in the last thirty years is neonicotinoids. This study's objective was to determine the effect of thiamethoxam, lambda cyhalothrin and their combination on biochemical parameters, the levels of free radicals and enzymes activities liver of male.Forty Rats ( 150-170 g ) were used. animals Were separated into four groups, each with ten rats.The Gp1 was used as control, the Gp2 was used to study the effect of thiamethoxam for 3weeks, the Gp3 was employed to examine the impact of lambda cyhalothrin for 3 weeks and the Gp4 was used to research the impact of thiamethoxam and lambda cyhalothrin for 3 weeks. thiamethoxam and/or lambda cyhalothrin significantly decreased the activity of glutathione S-transferase, catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, and reduced glutathione content in the kidneys of rats. The protein content in the kidney tissues of rats treated with thiamethoxam and/or lambda cyhalothrin decreased. An increase in the level of urea and creatinine was also observed in the blood serum of rats treated with thiamethoxam and/or lambda cyhalothrin . The results showed clear changes in red blood cells in the liver and kidney tissues of rats treated with thiamethoxam and/or lambda cyhalothrin .