Laparoscopic surgery of the horseshoe kidney has been limited to benign conditions, hand assistance, and retroperitoneal approaches for small tumors. In this case, we describe a pure transperitoneal approach to heminephrectomy for a large renal cell carcinoma. The operative considerations include identification of all arterial branches and careful isthmus dissection. Preoperative angiography may aid surgical planning. A pure transperitoneal approach to cancer surgery of the horseshoe kidney is effective.