【Abstract】 Objective To investigate the effectiveness of a percutaneous release with L shaped hollow needle knife in treating trigger finger. Methods Between September 2007 and September 2009, 160 patients with trigger fingers (202 fingers) were treated by percutaneous release with L shaped hollow needle knife. There were 47 males and 113 females with a mean age of 55 years (range, 12-68 years). The disease duration was 2 weeks to 1 year. Affected fingers included 58 thumbs, 20 index fingers, 46 middle fingers, 60 ring fingers, and 18 little fingers. According to Quinnell grading, 63 fingers were classified as grade III, 126 fingers as grade IV, and 13 fingers as grade V. A1 pulley was released during operation and steroid was injected after release procedure using the same needle. Results The mean operation time was 8.2 minutes (range, 5-19 minutes), and no complication occurred. All the patients were followed up 1 year to 3 years and 6 months (mean, 1.6 years). The patients still felt pain in 36 fingers at 1 week after operation, which were relieved after oral administration of non-steroidal anti-inflammatory drug. Twenty-five fingers had snapping or locking in flexion-extension motion; 5 fingers recovered at 1 month after operation and 20 fingers had no obvious improvement; of 20 fingers, symptom was alleviated in 10 fingers, and was not alleviated in 10 fingers after re-release with L shaped hollow needle knife. According to Quinnell grading for efficacy evaluation at 6 months after operation, the results were excellent in 165 fingers, good in 27 fingers, poor in 10 fingers with an excellent and good rate of 95.0%. Conclusion The percutaneous release with L shaped hollow needle knife is a safe and effective procedure in treating trigger finger with low complications.