BACKGROUND: The da Vinci robotic system (Intuitive Surgical, Sunnyvale, CA) has been used effectively and with good results. Previously, the surgeon could manipulate three arms on the robot: one camera port and two working ports. This configuration required a second surgeon for most general surgical procedures. Recently, the robotic device has been modified to include a fourth arm, adding another computer-assisted instrument that the surgeon can manipulate. In this report, we describe our experience with the da Vinci robot with a fourth arm modification for the performance of selected surgical procedures. MATERIALS AND METHODS: A total of six patients were prospectively enrolled and underwent surgery using the modified da Vinci robot. Their average age was 56 years. Five patients underwent Nissen fundoplication, and one patient underwent Heller myotomy. Operative time, defined as the time from skin incision to completed skin closure, as well as robotic time, defined as the time during which the robot was being used, were recorded. Intra-operative and perioperative complications were also recorded. RESULTS: Average operative and robotic times for Nissen fundoplication were 134 and 80 minutes, respectively. Operative and robotic times for the Heller myotomy were 118 and 70 minutes. All patients tolerated the procedure well and experienced no perioperative complications. CONCLUSIONS: The da Vinci robot with the addition of the fourth arm results in a efficient and safe operation and allows the surgeon to perform additional maneuvers without the use of a surgical assistant.