Acetochlor, an emerging herbicide is frequently used on maize and different other cereal crops to control weeds. Due to extensive and persistent applications, acetochlor may enter into nearby aquatic ecosystem and cause adverse effects on different animals. The residues of this herbicide via food chain can induce toxic impacts on different animals including public health. Therefore, it is crucial to investigate the toxic effects of acetochlor in exposed organisms. The current trial was aimed to know the deleterious effects of acetochlor in fresh water fish. A total of 80 fish were obtained and indiscriminately retained in 4 groups each containing 20 fish. Fish retained in groups (B-D) were exposed to acetochlor mixed in water @ 300, 400 and 500 µg/L respectively. Blood and different visceral tissues were collected at days 12, 24 and 36 of trial for hematological and histopathological studies. Different behavioral and physical ailments were observed in a time and concentrations manners. Results exhibited significantly (P<0.05) lower hematological profile including erythrocyte counts, hemoglobin, monocyte and lymphocyte count. The serum biochemistry analysis exhibited that the quantity of liver function tests, renal function tests, cholesterol, glucose, and triglyceride in treated fish increased significantly (P<0.05). Histopathological observation showed necrosis, increased Bowman’s space and renal tubular degeneration in kidneys. Various microscopic ailments in liver like, hemorrhages, edema, atrophid hepatocyte and hepatocyte with eccentric nuclei were observed in exposed fish. Necrotic neurons, microgliosis and degeneration of neurons in brain while hemorrhages, edema, and neutrophilic myocarditis was observed in heart of treated fish. The findings of our experimental research suggested that acetochlor exerts toxic effects on fresh water fish.