The clinical features of progressive lacunar infarction were analyzed in 20 patients with lacunar infarction. Seven of the 20 patients experienced paresis progression and the remaining 13 patients had a stable course. The mean age of progressive lacunar infarction patients (78.6 +/- 4.30 yrs) was significantly higher than that of stable lacunar infarction patients (65.1 +/- 7.68 yrs) (p < 0.01). Patients presenting with pure motor stroke were more likely to have progressive stroke (7/13) than those presenting with sensorimotor stroke (0/7) (p < 0.05). Paresis aggravation began on Day 1 and ceased on Day 2 in most patients. Progressive paresis began to improve after reaching the nadir. Hemiparesis was only slightly worse after 1 month compared with that on admission. Older patients are more likely to have a progressive course. Paresis progression in lacunar patients does not preclude the possibility of recovery and is not necessarily associated with a poor prognosis.