OBJECTIVE: To investigate the protective effect of hesperidin on retinal damage induced by traumatic head injury. STUDY DESIGN: Thirty rats were divided into 3 groups: control, trauma, and trauma+hesperidin. The control group received only saline for 7 days without injury. Craniotectomy was created under anesthesia in the trauma group and the rats were administered intragastrically with saline solution for 7 days. In the trauma+hesperidin group, after craniotomy, 30 mg/kg hesperidin was administered for 7 days. At the end of the experiments, blood samples were collected and retinal tissues were processed. RESULTS: After trauma injury, hesperidin treatment reduced MDA and MPO values and increased GSH content in the trauma+hesperidin group. Dilation, inflammation, degenerated ganglion and photoreceptor cells, and Bcl-2 and TNF-α expressions were decreased in the trauma+hesperidin group. Hesperidin administration improved histology of the retina mostly in the trauma+hesperidin group. CONCLUSION: It has been predicted that hesperidin is effective in the regulation of cytokine activity, the TNF reaction, and the reduction of cell apoptosis triggered afterwards. It has been thought that the apoptotic process, which progresses in the direction of cell degeneration, may have a slowing effect in the nuclear loss phase of hesperidin treatment. © Science Printers and Publishers, Inc.