Hypersplenism may occur in patients with a variety of haematologic, inflammatory, metabolic and neoplastic disorders and in patients with chronic congestive splenomegaly due to portal hypertension. Untreated hypersplenism due to congestive splenomegaly carries a 5-year survival rate of only 50%. Hypersplenism can be treated by various modalities; including splenectomy, partial splenic embolization, Transjugular intrahepatic portosystemic shunt (TIPS), Splenic irradiation, GM-CSF (Granulocyte-Macrophage Colony-Stimulating Factor), Erythropoietin, Thrombopoietin and Liver transplantation. Methods: This study included 30 patients with congestive hypersplenism. The spleen was irradiated with 150 cGy per sitting daily for 10 days. The hematological parameters were estimated before, during, immediately after, 4 weeks after irradiation and at the end of study. Also, the spleen volume and splenic pain were assessed before irradiation and at the end of study. Results: This study has clearly shown that splenic irradiation has a significant increase in the number of RBC and platelets immediately and 4 weeks after splenic irradiation as well as significant reduction in the spleen size 20 weeks after spleen irradiation without having significant effects on Hemoglobin or WBC. Also, there is significant improvement of the splenic dragging pain in all patients. Although, at the end of our study, all hematological parameters and splenic size did not show any significant improvement. Conclusion: there are many suggested treatments for hypersplenism including; Splenic irradiation, but its effect is partially and temporary. Splenic irradiation as a sole modality is not satisfactory in treating hypersplenism, so combination of different modalities may be needed.