Introduction: Internal carotid artery dissection (ICAD) is a rare cause of acute ischemic stroke with large vessel occlusion (AIS-LVO). We aimed investigating the impact on outcome of internal carotid artery (ICA) patency after mechanical thrombectomy (MT) for AIS-LVO due to occlusive ICAD. Patients and methods: We included consecutive patients with AIS-LVO due to occlusive ICAD treated with MT from January 2015 to December 2020 in three European stroke centers. We excluded patients with unsuccessful intracranial reperfusion after MT (modified Thrombolysis in Cerebral Infarction (mTICI) score < 2b). We compared 3-month favorable clinical outcome rate, defined as a modified Rankin scale (mRS) score ⩽2, according to ICA status (patency vs occlusion) at the end of MT and at 24-h follow-up imaging, using univariate and multivariable models. Results: Among 70 included patients, ICA was patent in 54/70 (77%) at the end of MT, and in 36/66 (54.5%) patients with 24-h follow-up imaging. Among patients with ICA patency at the end of MT, 32% presented ICA occlusion at 24-h control imaging. Favorable 3-month outcome occurred in 41/54 (76%) patients with ICA patency post-MT and in 9/16 (56%) patients with occluded ICA post-MT (p = 0.21). Rates of favorable outcome were significantly higher in patients with 24-h ICA patency compared to patients with 24-h ICA occlusion (32/36 [89%] vs 15/30 [50%]), with an adjusted odds ratio of 4.67 (95% CI: 1.26–17.25). Discussion and conclusion: Obtaining sustained (24-h) ICA patency after MT could be a therapeutic target for improving functional outcome in patients with AIS-LVO due to ICAD.