Ganglioglioma is an uncommon central nervous system tumor. The role of adjuvant postoperative radiation therapy is undefined. The authors retrospectively reviewed the clinicopathologic features and results of therapy for 34 patients with ganglioglioma treated at the University of California at Los Angeles. There were 18 women and 16 men. Median age was 18 years. Twenty-five tumors were low grade. Twenty-one patients underwent gross total resection. Three patients received adjuvant radiotherapy. The 4-year actuarial progression free and overall survival rates were 67% and 75%, respectively. The median time to progression was 14 months and all relapses were local. Factors significantly influencing progression-free or overall survival according to univariate analysis included degree of resection and tumor grade. Survival and relapse were not significantly influenced by any factor according to multivariate analysis. The progression-free survivals after gross total resection of low- and high-grade tumors were 78% and 75%, respectively. Respective rates after subtotal resection were 63% and 25%. Review of the literature demonstrates no role for radiotherapy after total resection of ganglioglioma or after partial removal of low-grade tumor. Radiation therapy appears to reduce the relapse rate after partial removal of high-grade lesions. A dose in excess of 5,000 cGy is necessary for ganglioglioma.