From a series of 571 patients with herniated lumbar intervertebral discs operated upon the author selected 128 cases that had been carefully observed during a period of at least one year. The results were classified as good, regular and poor ones. Good results, i.e., without any remaining signs or symptoms, were obtained in 78.1% (100/128) of the cases; regular results with emaining signs and symptoms, less evident than preoperatively, represents 10.9% (14/128) of the cases; no relief of the previous signs and symptoms was verified in 10.9% (14/128) of the cases. The author emphasizes that surgical approach is indicated (1) when the conservative treatment is ineffective, (2) when sensory or motor deficits are evident and finally, (3) when acute damage of several nerve roots is present. Myelography must always be added to the clinical examination since it will give the site and extension of the lesion as well as the elements for differential diagnosis. Once indicated the operation must be carried out by trained neurosurgeon. Special attention is dedicated to the description of the technical details concerning the surgical act.