Renal artery aneurysms can have variable presentations, often resulting in a therapeutic dilemma to the clinician. We review the causes, clinical features, pathological conditions and treatment options for this problem. We report a case of a thrombus in 1 of 2 left renal arteries, which resulted in uncontrollable hypertension. At nephrectomy the angiographically normal vessel had medial degeneration, demonstrating the diffuse nature of this disease. Conservative renal-sparing management should be considered whenever possible.