In order to identify prognostic factors of survival, twelve elements of disease and treatment have been evaluated for a population of 49 patients with diffuse low-grade astrocytoma treated with surgical resection and radiotherapy. The survival values were inversely correlated with age and major residual portion. On the other hand, KPS, lobar site, grade II Daumas-Duport lesions, protoplasmatic variant, early epilepsy, hyperfractionated radiotherapy and extent of exeresis were prognostic factors correlated with survival. Tumor extent and radiation total dose were not correlated in a meaningful way. Only KPS was statistically significant when compared to all the prognostic factors. We believe that patient selection according to age, lesion site and histological features are not sufficient to generate a homogeneous tumoral population. The most appropriate therapy for treating low-grade astrocytomas is still an open subject. However, recent studies have shown that the prognostic value of a group of factors is useful to plan controlled studies that compare differentiated treatment protocols.