Isolated internal iliac artery aneurysms are rarely described in the available literature. The paper presents a case of a 70-year-old female with idiopathic thrombocytopenia, squamous cell cervical carci-noma, and saccular aneurysm of the left internal iliac artery, detected in magnetic resonance. The review of aneurysm of the common, external and internal iliac arteries is added.