We report a case of solitary pelvic kidney encountered during laparoscopic colectomy. A 55-year-old man was admitted to undergo laparoscopic colectomy for an early sigmoid colon cancer, which had been detected after a polypectomy. The kidneys were not clearly visualized in their normal position by ultrasonography. During the operation, anomalous vessels in the presacral space and a mass covered with fatty tissue were identified. We converted the operation to a mini-laparotomy, and on performing intraoperative ultrasonography a solitary pelvic kidney was detected. An anterior resection was performed without operative complications. Laparoscopic ultrasonography (LUS) and hand-assisted laparoscopic surgery (HALS) should be considered as feasible adjuvants, when difficult situations arise during laparoscopic colectomy. In case of uncertainty about anatomical orientation or identification, it is prudent to convert to open surgery thereby preventing intraoperative complications such as injury to anomalous vessels or the ureter.