Abstract: Background: Over the years, pyrethroids, including allethrin, are widely used for domestic and agricultural purposes and are found to be neurotoxic. However, effects on hematological and biochemical parametersare not elucidated. Thus, the first objective of the present study was to investigate the effect of allethrin on the hematological and biochemical parameters of Swiss albino mice. Further, for the amelioration of its effect, two different bioactive herbal extracts piperine (alkaloid) and curcumin (polyphenols) were evaluated. Methods: Animals were divided into six groups; the first group was used as a control. Groups 2, 3, 4, 5 and 6 were orally treated with allethrin (15 mg kg-1 b.wt.), allethrin+curcumin (100 mg kg-1 b.wt.), allethrin+piperine (100 mg kg-1 b.wt.), piperine (100 mg kg-1 b.wt.) and curcumin (100 mg kg-1 b.wt.), respectively for 28 days. Results: Administration of allethrin brought about a significant decrease in leukocytes, polymorphs, serum albumin, HDL, glucose and CPK and whereas, lymphocytes, haemoglobin, ALT, AST, serum creatinine, blood urea, total cholesterol, LDL, VLDL, triglycerides was found to be significantly increased following allethrin treatment. Gravimetric indices (body weight and organ weight) slightly declined following allethrin treatment. Further, the histopathological observations in allethrin treated mice showed the damage in all vital organs (kidney, liver, lungs, brain and heart) of Swiss albino mice. Administration of piperine and curcumin exhibited signi cant reversal of allethrin altered hematological and biochemical parameters. ALT, AST, serum creatinine, blood urea, serum albumin, HDL, glucose found to be comparable to that of the control group after piperine and curcumin administration. The presence of piperine and curcumin with allethrin preserved the normal histological architecture of the liver, kidney, lungs, brain and heart. Conclusion: These results indicate that piperine and curcumin can be a potent protective agent against allethrinalteredbiochemical and hematological alterations in mice.