Abstract Background and purpose We retrospectively evaluated the therapeutic outcomes of patients with primary spinal cord astrocytomas treated with conventional radiotherapy at our institute. Patients and methods Between May 1975 and December 1997, 26 patients with histologically proven spinal cord astrocytomas were treated with conventional radiotherapy, and twenty-four eligible patients were evaluated. Median age was 19 years (2–41 years). Fourteen of astrocytomas were grade I, 6 of them grade II and 4 grade III. Ten patients had subtotal excision, and 14 had only biopsy of the primary lesion. Patients were treated with 1–2 Gy daily fractions, and given to a median total dose of 49.5 Gy (range 35–60 Gy) external radiotherapy to primary tumor. Results Median follow-up was 39 months. Seventeen patients died of their disease. Two patients have progression, and 5 patients are followed with stabile disease. Five-year overall survival was 45% and progression free survival was 40%. Among the analyzed factors only gender and age were found to be significant. Conclusions Our results are slightly worse than previous retrospective radiotherapy series in the literature. With new imaging and radiation therapy techniques, radiotherapy may have a role as an adjuvant treatment especially in subtotally resected tumors.