OBJECTIVE: To investigate the changes in the retina due to deltamethrin toxicity and the process in cell inflammation and apoptosis. STUDY DESIGN: Sixteen Wistar albino rats were randomly divided into two groups as control (n=8) and deltamethrin (n=8) groups. Saline was given to the control group, and 0.5 mL of 5 mg/kg deltamethrin was given to the deltamethrin group for 14 days each. Blood was collected for biochemical analysis. Retinal tissue was processed for histological examination. RESULTS: Compared to the control group, MDA levels were high while GSH and CAT levels were low in the deltamethrin group. Histopathological analysis showed spaces between the pigment epithelium, irregularity in the delimiting membrane, degenerated ganglion, cone and bacillus cell, pyknotic nuclei, thinned inner limitation membrane, and thickened vascular wall. The control group showed FAS expression in the pigment layer limiting membranes, in the nuclei of many cone and bacillus cells, and ganglion cells in the control group sections. In the deltamethrin group, FAS expression was observed in the inner and outer limiting membranes of the pigment epithelium, cone and bacillus cells, and ganglion cell nuclei. In the control group, negative NOS expression in the pigment epithelium and outer limiting membranes, internal limitation membrane, and ganglion cells in the cone and bacillus cell nuclei were observed. In the deltamethrin group, NOS expression was positive in the pigment epithelium, cone and bacillus, and ganglion cell nuclei. CONCLUSION: We suggest that deltamethrin toxicity induced apoptotic process due to increased inflammation in the retina and may cause visual impairment as a result of neural damage. © Science Printers and Publishers, Inc.