The authors have studied 34 cases of reticulum cell sarcoma of the spinal epidural space. This pathological entity was more frequent in males over 50 years of age. However younger patients can be affected, especially from 15 to 29 years. The commonest place where they happen is the dorsal region and this is a good point for a differential diagnosis of the spine expanding lesions. Pain of radicular type was the most important complain in 15 patients. In our series this was the first symptom while all the others came out later on many months or even years. The spinal epidural reticulosarcomas were classified in three groups according to their cellular appearances and particularly to the presence of reticulin. It is remarkable that patients which had group III tumors showed a longer survival period than those presenting other reticulosarcomas, possibly because Group III neoplasms grow slowly. In spite of different types of reticulosarcomas, they have a satisfactory outcome if an early diagnosis is made and if they are adequately treated.