BACKGROUND Splenic irradiation is an accepted mode of treatment for palliation of hypersplenism and splenic pain for patients with lymphoproliferative or myeloproliferative disorders. However, results are conflicting regarding the duration of palliation and the toxicity associated with this treatment. METHODS Twenty-five patients with lymphoproliferative or myeloproliferative disorders were treated with splenic irradiation for palliation of splenomegaly and pain. The spleen was measured and pain and toxicity were assessed during radiation therapy. RESULTS Splenomegaly and splenic pain decreased in 60 percent and 91 percent of patients, respectively. Radiation doses higher than 500 cGy appeared to be more effective than lower doses in reducing the spleen size in patients with chronic lymphocytic leukemia. Regression of splenomegaly and pain relief were maintained for less than one year and more than six months, respectively. Acute radiation toxicity resulted in the cessation of radiotherapy in two patients. CONCLUSIONS Splenic irradiation is effective in the short-term palliation of splenomegaly and pain and may be most useful in the subset of patients with a life expectancy of less than one year. Terminally ill patients with splenomegaly secondary to lymphoproliferative or myeloproliferative disorders may benefit from splenic irradiation to minimize pain and pressure symptoms in addition to possible reduction of narcotic use.