OBJECTIVE To study toxic effects of 2,5-hexanedione (2,5-HD) on pathology and lipid peroxidation in mouse retina. METHODS Forty-eight mice were randomly divided into blank control group (12 mice), negative control group exposed to normal solution (12 mice) and group exposed to 2,5-HD for 2. 4 and 8 weeks, respectively (24 mice) by intraperitoneal injection (2.5% 2,5-HD) at the dose of 400 mg/kg. The pathological changes of mouse retina were examined under light microscope. The activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) in mouse retina were detected. RESULTS The retinal structure in the blank and negative control groups was normal. In mice exposed to 2,5-HD for 8 weeks, the swelling of outer and inner segments and disorder arrangement of the segments without clear boundary were found. The staining of outer plexiform layers was uneven and the irregular loose structure appeared. The hyperchromatic pyknotic and necrosis nuclei were presented in ganglion cells layer. Compared with the control and blank groups, the activities of SOD gradually and significantly reduced and the concentrations of MDA increased in group exposed to 2,5-HD (P < 0.05). CONCLUSIONS 2,5-HD can induce the injury of retina tissues of mice, which may be associated with the lipid peroxidation.