The aim of this study was to analyze the survival of a series of patients diagnosed as having brain stem tumors by computerized tomography scan, magnetic resonance imaging and/or biopsy and treated with megavoltage irradiation. Fifty-three patients presenting to the Peter MacCallum Cancer Institute with a diagnosis of brain stem tumor from January 1980 to July 1989 were reviewed. There were 32 pediatric (age < or = 16) and 21 adult patients. The median age at presentation was 12 years (range 2-73 years). Eighteen patients had biopsy proof of glioma, the rest were diagnosed on the basis of CT and/or MRI appearance. Eighty-seven percent of patients received 44-55 Gy in 1.67-2.25 Gy fractions to the brain stem. Seventy-seven percent of patients showed improvement following treatment, 6% were stable, 11% progressed, and 6% were not evaluable. The estimated median survival from presentation for all patients was 34 months with 49% surviving at 3 years. The estimated median time to progression was 19 months with 34% not progressed at 3 years. There was no significant survival difference between patients with biopsy-proven glioma and those patients where the diagnosis was made radiologically. Survival was not significantly affected by age-group or sex. Patients with symptoms for more than 9 months prior to presentation had significantly longer survival than those with shorter duration of symptoms (p = 0.002). This paper presents the survival of patients with brain stem tumors diagnosed and treated by contemporary radiological and radiotherapeutic techniques.