This prospective study was designed to test the sonographically assisted percutaneous release (SAPR) technique to release the Al pulley in trigger digits. A series of 218 patients received 257 SAPR procedures between September 2001 and April 2003, and all patients were evaluated for immediate clinical results and complications. Of the 251 digits of 213 patients available for follow-up, pain was completely relieved in 241 digits (96.0%), and the other ten digits (4.0%) had improved remarkably. The mechanical problems were resolved in all digits. There were no significant complications and no recurrence during follow-up. We conclude this new procedure allows the surgeon to avoid the inherent risks of traditional percutaneous release and achieve a high rate of success with minimal morbidity.