OBJECTIVE: Two mechanical thrombectomy techniques are proposed for tandem occlusion of the anterior circulation: treating the extracranial carotid artery lesion first via an antegrade approach and treating the intracranial lesion first via a retrograde approach. Previous reports show that the retrograde approach has a shorter reperfusion time and a better prognosis, but re-occlusion of the intracranial lesion after recanalization may occur. We describe a case of tandem occlusion with repeated intracranial occlusions for mechanical thrombectomy using the retrograde approach and discuss possible countermeasures. CASE PRESENTATION: A 94-year-old woman presented with acute cerebral ischemia due to tandem carotid T occlusion of the left internal carotid artery (ICA) and severe stenosis of the cervical carotid artery. Mechanical thrombectomy via a retrograde approach was performed using a stent retriever, resulting in complete recanalization of the anterior circulation through the ICA after 1 pass. The thrombus dispersed distally from the cervical artery and re-occluded the M1 twice, requiring thrombus re-retrieval each time. CONCLUSION: The retrograde approach to tandem occlusion can result in repeated re-occlusion after recanalization of the intracranial lesion. Thrombi in cervical carotid lesions are usually fragile. Prior thrombus aspiration from the balloon guiding catheter at the carotid lesion may prevent re-occlusion after recanalization of the intracranial lesion without sacrificing the time advantage of early recanalization via the retrograde approach.