Aim: Piriformis syndrome is a rare neuromuscular disorder that occurs when the piriformis muscle compresses or irritates the sciatic nerve. The treatment of piriformis syndrome includes injections into the piriformis muscle around the sciatic nerve. These invasive approaches have been used with various techniques to increase the safety of the procedure. Computed tomography (CT)-guided injection of the piriformis muscle and the clinical outcome of the patients are discussed. Ma terial and methods: The authors presented 10 consecutive patients that underwent CT-guided piriformis injection between March and December 2007. Three patients had a history of a severe fall on the buttocks, one had gluteal abscess formation following deep intramuscular injection, and another one had a habit of prolonged sitting on the carpet. Etiology was not identified in the other patients. Main complaints of the patients were pain and numbness in the legs. Hypesthesia was the major neurological finding. Magnetic resonance imaging (MRI) and electromyography (EMG) were performed in all patients. Results: Nine patients had full and sustained recovery of their symptoms after piriformis injection. Only the patient who had gluteal abscess formation following deep intramuscular injection showed moderate improvement. Another patient was operated on in the 6th month after piriformis injection due to an extruded disc herniation. Conclusion: CT-guided piriformis injection is a safe and effective method in the treatment of piriformis syndrome.