📕 The study was aimed to investigate the effect of deltamethrin and fluoride alone & their combination on different blood biochemical & antioxidant parameters in wistar rats. 24 healthy rats of either sex weighing 150-200G were divided in 4 groups with 6 rats in each group. Group I were untreated and served as control. Group II received deltamethrin orally @ 1.28 mg/kg, BW (1/100 of LD50) daily for 4 weeks. Group III was administered sodium fluoride @ 44.5 mg/ L in drinking water (providing 20 ppm of fluoride in water) daily for 28 days. Group IV received both deltamethrin & fluoride at the same doses and manner as in groups II & III. Deltamethrin alone elevated the levels of SGOT & SGPT whereas fluoride increased AST and proteins. Both toxicants alone decreased the levels of erythrocyte AChE activity. However, co-administration of deltamethrin and fluoride elevated plasma enzymes more prominently. Among the stress parameters, significant increase was observed in LPO & GST activity but significant decrease in activities of GSH-Px, SOD & CAT. The observations indicate that both deltamethrin & fluoride alone & in combination induce marked alterations in biochemical & stress parameters.