The aim of this paper is to report an unusual case of a patient with an abdominal aortic aneurysm (AAA) and a hydronephrotic horseshoe kidney (HSK) that was repaired by endovascular means. An 81-year-old male patient with a known HSK was found to have hydronephrosis and an AAA. The patient's aneurysm was treated with an endovascular stent graft which required the covering of accessory renal arteries. He had an uneventful recovery with complete resolution of the hydronephrosis evident on a computed tomography scan performed seven months after the surgery. In conclusion, endovascular aneurysm repair is a feasible therapeutic option for an AAA coexisting with an HSK and may be considered as a valid alternative to open repair when concomitant hydronephrosis is present.