Fifty consecutive patients with intractable sciatic pain, positive root tension signs, correlative myelography, and neurological impairment were treated by percutaneous lateral discectomy (PLD). Under local anesthesia and C-arm fluoroscopy control, an 18-gauge needle, introduced into the intervertebral disc dorsolaterally, entered the skin at approximately 9 cm from the midline. A Kirschner wire replaced the stylet of the needle, and the needle was withdrawn. The introduction of a specially designed cannulated trocar over the K-wire facilitated precisional insertion of the instruments. This step was followed by the introduction of a sheath with an internal diameter of 4.9 mm over the trocar. The sheath was held against the annulus fibrosis, and the cannulated trocar was removed. The annulus was windowed and the herniated disc material evacuated by instruments and suction. Evaluations were made with Macnab's criteria. Excellent and good results were obtained in 88% of patients. The mean length of hospital stay after operation was 2.3 days. The operative time, blood loss, and morbidity were minimal, and no serious complications were encountered. In carefully selected patients, PLD appears to be safe, effective, and cost-efficient.