BACKGROUND/PURPOSE: One-trocar surgery (OTS) includes all video-surgical techniques performed using a single 10-mm port and an operative scope. These techniques can be completely endoscopic or endoscopic assisted. Since 1997, OTS has become the approach of choice in our institution for a variety of laparoscopic, retroperitoneoscopic, and thoracoscopic operations. We report our experience with this technique. METHODS: Four hundred fifty-eight patients (age range, 3 months to 17 years) underwent OTS from October 1997 to December 2008. The procedures were transumbilical laparoscopic-assisted (TULA) appendectomy (182 patients), TULA small bowel resection (14 patients), TULA intestinal biopsies (7 patients), laparoscopic adhesiolysis (6 patients), laparoscopic-assisted liver biopsies (5 patients), laparoscopic revision of peritoneal dialysis catheter (3 patients), retroperitoneoscopic varicocelectomy (202 patients), retroperitoneoscopic-assisted renal biopsies (4 patients), retroperitoneoscopic drainage of posttraumatic urinoma (1 patient), retroperitoneoscopic-assisted pyeloplasty (15 patients), and thoracoscopic pleural debridement and decortication for empyema (19 patients). RESULTS: The procedure was completed using only one trocar in 399 cases (87.1%). All conversions to multitrocar or open surgery were elective and regarded the retroperitoneoscopic approach during the learning curve (28 of 222, 12.6%; 21 varicocelectomies and 7 pyeloplasties) and the TULA appendectomy because of the appendix mobilization failure (31 of 182, 17%). There were no intraoperative or postoperative complications related to OTS. Wound infection was observed after two TULA appendectomies (1.3%). CONCLUSIONS: According to our experience, OTS is a feasible and versatile technique in pediatric surgery, providing a safe, effective, and the least invasive treatment for several different diseases.