In 57 patients with astrocytoma grade I and in 65 patients with astrocytoma grade II, operated on between 1978 and 1988, diagnosis and follow up was based on computerized tomography (CT). The follow up period ranged from one to 13 years, mean follow up was 59 months for grade I and 41 months for grade II tumors. Histological differentiation between both grade I and grade II proved to have the highest prognostic value. The five year survival rate was 85% in grade I and 50% in grade II. Preoperative clinical findings were highly correlated with outcome. Age was found to be of low prognostic value. CT findings were not clearly related with survival. It is concluded that surgery should not be delayed, until more severe symptoms arise, since prognosis is better with lesser preoperative neurological deficits.