Ultrasonography and computed tomography were used to diagnose, localize, and guide the percutaneous drainage of 24 intraabdominal and retroperitoneal abscesses in 23 surgical and medical inpatients 16 of whom had abscess formation as a postoperative complication. On the basis of anatomic detail from sectional imaging, safe percutaneous drainage routes similar to surgical approaches were defined. After confirmation by needle aspiration, one of two methods of percutaneous catheter introduction were used: (1) a modified Seldinger technique for placement of an 8 French pigtail catheter and (2) a trocar catheter technique for placement of a 12 or 16 French catheter. Once in position, the catheters were managed as a surgically placed drain. In 22 of 24 cases, percutaneous catheter drainage was curative with no surgery required. There were no deaths or recurrences with an average follow-up period of 12 months ranging from 1 week to 3 years. Percutaneous aspiration and drainage should be considered as an alternative to surgery in the treatment of intraabdominal or retroperitoneal abscess.