To assess outcomes of mechanical thrombectomy (MT) in nonagenarians suffering from acute ischaemic stroke (AIS) in a 1-year follow-up. Age is a factor associated with both the occurrence of AIS and a poorer prognosis. As the population ages, the prevalence of AIS among the very old (90 and older) is expected to rise. Data on long-term outcomes of MT, being the optimal treatment of AIS caused by large vessel occlusions, is scarce in the population of nonagenarians. We analysed all AIS patients treated with MT in a single Comprehensive Stroke Centre. We compared two subgroups: nonagenarians (people aged 90-99) and controls ( < 90 years) in terms of cardiovascular risk factors profile, stroke severity, treatment course, presence of in-hospital complications, and outcomes (mortality and good functional outcome defined as modified Rankin Scale ≤ 2) at discharge and at 90- and 365-day follow-ups. Nonagenarians were more commonly female and suffering from atrial fibrillation. They more often developed urinary tract infection during hospitalisation. Stroke severity, treatment course and in-hospital outcomes were comparable between the groups. Nonagenarians had non-significantly higher 90-day and 365-day mortality, and a significantly lower rate of good functional outcomes after 90 days (25.0% vs 57.7%, p = 0.011) and 365 days (31.5% vs 61.0%, p = 0.020). Despite worse outcomes than in younger patients, 25% of nonagenarians were functionally independent three months after MT, and almost one in three of them were so a year after the procedure, thereby showing the benefits of the treatment in this group.