Horseshoe kidney is a rare renal fusion anomaly, and because of limited mobilization of the kidney and its multiple arterial blood supplies, minimally invasive surgery for renal tumors can be challenging. We describe a case of a right-side oncocytoma in a horseshoe kidney managed robotically and review the literature of robotic-assisted laparoscopic surgical resection of kidney tumors in renal fusion anomalies. Robotic-assisted laparoscopic partial nephrectomy in a horseshoe kidney is feasible. Fusion-related limited mobility during the procedure, as well as an extremely variable blood supply, require meticulous planning. Multi-phase computed tomography and interactive 3D anatomical models are helpful tools to prepare for surgery.