Iliacus compartment syndrome is a rare retroperitoneal compartment neuropathy caused by bleeding within the iliacus muscle leading to hematoma formation and compression upon the femoral nerve, causing both sensory and motor deficits. A 75-year-old Caucasian man presented with severe right hip pain associated with motor and sensory deficit in the right lower extremity, 2 weeks post elective balloon aortic valvuloplasty for critical aortic stenosis. A non-contrast computed tomography scan revealed low-attenuation areas in keeping with an iliacus hematoma. An iliacus fasciotomy and hematoma evacuation was performed with retroperitoneal approach. The patient reported marked reduction in his groin pain with clinical improvement of the right hip flexion though the sensory deficit was unchanged. On Day 3, postoperatively the patient died from respiratory and multi-organ failure. Iliac hematomas are rare and can be caused by traumatic and non-traumatic injury, and can be exacerbated by complications of anticoagulant therapy. Delaying surgical evacuation of the hematoma can lead to prolonged or permanent disability. However, there are other reports describing good recovery with non-operative management. Non-surgical intervention is recommended if radiological studies do not explicitly confirm the presence of a discreet hematoma compressing the femoral nerve, unless progression of symptoms increases.