To investigate the influence of leukoaraiosis (LA) on the functional outcomes of subcortical stroke in the subacute phase after onset. We retrospectively analyzed 41 patients with subacute subcortical infarct at a single center from 2011 to 2015. We explored the relationship between LA severity at admission/transfer (initial evaluation) and functional outcome at the time of discharge (follow-up evaluation), as assessed using the modified Rankin Scale (mRS), Functional Ambulation Category (FAC), and modified Barthel Index (mBI). LA severity was graded as mild, moderate, or severe according to the Fazekas scale. Scores of the mRS, FAC, and mBI were compared in patients grouped based on LA severity: no LA (n = 12), mild LA (n = 19), and moderate-to-severe LA (n = 10). Significant inter-group differences were observed in all 3 scores at both the initial and follow-up evaluations. After adjustment for age, scores at follow-up evaluation were significantly different between the 2 groups. LA is related to functional outcomes of subcortical stroke in the subacute phase after onset. After adjustment for age, severe LA was correlated with poor functional outcomes in the subacute phase.