Background: While procarbazine, CCNU and vincristine (PCV) has been shown to be efficacious in the treatment of anaplastic oligodendroglial tumors (AOT), the question of whether procarbazine and CCNU (PC) alone is sufficient still exists, since vincristine has been argued to add toxicity with little if any clinical benefit. This retrospective study was designed to provide initial insight into the comparison of PC with and without vincristine. Methods: Using the Brain Tumor Center historical database, we queried patients diagnosed with (AOT) treated at MD Anderson Cancer Center from June 1, 1993 through October 13, 2009. Patients were eligible if they had been diagnosed with a primary AOT and were subsequently treated with either PC or PCV at some point in the treatment regimen. A total of 120 patients were included in the study population, with 97 patients included in the primary analysis of treatment before first progression. Results: Initial treatment included radiation and chemotherapy (80.4%), chemotherapy alone (18.6%), or radiation alone (1.0%). Overall survival did not differ with initial treatment. 21 patients (21.6%) received PC during primary treatment, while 76 patients (78.4%) received PCV. 11 patients reported neurotoxicity in the PCV arm (defined as dysautonomia, peripheral neuropathy and ataxia), compared with none in the PC arm. Of the 97 patients included in the analysis, 45 were alive at last contact with a median follow-up of 9.9 years. The median overall survival (OS) time was 6.5 years (95% CI: 4.8-16.7 years). OS was significantly associated with KPS within one month of diagnosis (p=0.002) but not with age (p=0.26). There were 63 patients with disease progression or death, and the median progression-free survival (PFS) was 2.9 years (95% CI: 2.0-6.3 years). There was no difference between the two groups in OS (p=0.61) or PFS (p=0.28). Conclusions: Initial therapy with PC vs. PCV achieved comparable results with a median follow-up of 9.9 years. There was no difference in dose reductions although neurotoxicity was more frequent with vincristine. Further studies with correlative codeletion status are needed.