Radiotherapy or irradiation of SNC AVM's or tumors also presents a high risk for provoking lesions in adjacent surrounding tissue. The objective of our study is to demonstrate radiotherapy induced alterations in a rat spinal cord model and evaluate the protective effect of Growth Hormone (GH) on rats exposed to high radiotherapy doses. The experimental study employed two groups of Wistar rats: Group A (control group):10 rats, which received 30 Gy at the spinal cord . Group B: 10 rats, these animals received 30 Gy and dose of 2mg/kg/day GH. Growth hormone administration was begun three days before radiotherapy and continued until two days after radiotherapy for a total of six days. At 14 days postradiotherapy, all the rats were sacrificed and the spinal cord extracted immediately. Hematoxyline-eosine histologic studies showed that control animals only exposed to radiotherapy had severe alterations with hemorrhage and vacuolisation of the entire irradiated segment while these alterations were much less severe in the GH-treated group. In conclusion, 30 Gy irradiation produced morphological changes including vascular endothelial oedema, necrosis, hemorrhage, and inflammatory exudates. A 2 mg/kg/day dose of GH protected the rat spinal cord against the noxious effects of the radiotherapy, decreasing the clinical, macro and microscopic damage in the treated animals.