The clinical and radiological prognostic factors were investigated in 32 patients with newly diagnosed anaplastic oligodendroglioma treated by combined therapy using surgery, postoperative radiation therapy, and adjuvant chemotherapy between September 1994 and December 2002. Surgery aimed at total removal was followed by radiotherapy, and 3 weeks later by adjuvant chemotherapy repeated at 6- to 7-week intervals. Survival analysis showed that younger age, absence of preoperative headache, good postoperative Karnofsky Performance Status (KPS) score (>or=80), and relatively small tumor volume (<50 cm3) were predictors for longer survival in univariate analysis (p<0.05). Age and good postoperative KPS score were independent prognostic factors in multivariate analysis (p<0.05). Median survival was 58 months after diagnosis, and the 5-year survival rate was 49%.