Pollution is now a day has become a threat to living beings. Pollutants in the form of pesticide inhabit a variety of environments which affect the normal vital activities of organisms living. They reach the aquatic environment as a washout from agriculture fields as well as from industrial areas. Pesticide contamination in water may accumulate in the bodies of animals and affect the vital organs which alter the usual activities. Cypermethrin is a synthetic pyrethrum insecticide used in agriculture to control pest in crops such as lettuce and cotton and household pest such as cockroach. To understand the toxic effect of pesticides, it creates a need for histopathological observation of tissues. Present work was carried to evaluate the toxic effect of cypermethrin (25% EC) in liver and gills of tilapia (O.mossambicus). The fish experimented to different sublethal concentration of 1/10th,1/20th and 1/30th level of LC50 (4.5 mg/l) value of cypermethrin for 30 days. Gill exhibited epithelial cell damage, Fusion , Length reduction , Curling and Repturing of secondary gill lamellae, primary gill lamellae Enlargement, Necrosis, Cytoplasmic vacuolization, Damaged red blood corpuscle, Excessive secretion of mucus, whereas liver showed increased vacuolization, Necrosis, Hyperplasia, disintegration of hepatocytes and necrotic nuclei. Aim of the present study is to identify the effect of cypermethrin on organs tissues ( liver, kidney) of   freshwater fish, Oreochromis mossambicus. Keywords: Cypermethrin, Oreochromis mossambicus, Gill, Liver