The post-thrombotic syndrome is a serious complication of deep vein thrombosis. Post-thrombotic iliac venous occlusion (PTIVO) is rarely associated with an arteriovenous fistula (AVF); however, the underlying mechanism remains unclear. We reported three PTIVO cases associated with an AVF, two symptomatic cases treated with venous stenting, and one asymptomatic case followed up conservatively. The essential imaging findings to diagnose PTIVO with an AVF were the presence of an arterial waveform on ultrasound examination and early opacification on contrast-enhanced computed tomography in the iliofemoral veins. Venous stenting resulted in the disappearance of the AVF, drastic improvement in symptoms, and an excellent long-term outcome.