OBJECTIVE: Stroke in young adults is uncommon and rarely described. Moyamoya disease is one of the leading causes of stroke in young adults. We aimed to study the prognostic factors for stroke recurrences and functional outcomes in young stroke patients with moyamoya disease after revascularization. METHODS: We reviewed 696 consecutive patients with moyamoya disease admitted to our hospital from 2009-2015 and identified patients aged 18-45 years with first-ever stroke. Follow-up was conducted via face-to-face or structured telephone interviews. Outcome measures were recurrent stroke events and unfavorable functional outcomes (modified Rankin Scale >2). RESULTS: We included 121 young patients with moyamoya disease suffering from stroke (initial presentation age, 35.4 +/- 7.5 years). All patients underwent revascularization after the acute phase of initial stroke events as the secondary prevention for recurrences. During follow-up (median, 40 months), 9 patients (7.4%) experienced recurrent strokes and 8 of them (6.6%) suffered unfavorable functional outcomes. In the multivariate analysis, diabetes was an independent predictor for stroke recurrences (hazard ratio 6.76; 95% confidence interval 1.30-35.11; P = 0.02) and was significantly associated with unfavorable functional outcomes (odds ratio 7.87; 95% confidence interval 1.42-38.74; P = 0.01). CONCLUSIONS: We identified diabetes as an independent risk factor for recurrent strokes and unfavorable functional outcomes after revascularization in young stroke patients with moyamoya disease.