Clinical observation suggested to us that aphasia recovers relatively better than other deficits early after intravenous recombinant tissue plasminogen activator (IV-rtPA) treatment in stroke patients with minor deficits, while the reverse seemed the case in those with severe deficits. Retrospective analysis of acute ischemic stroke patients with aphasia admitted within 3 hours from symptom onset and treated with IV-rtPA was carried out. Stroke severity, aphasia and global neurological impairment were assessed at admission and 24 hours after thrombolysis. Improvement of aphasia (gain of ⩾ 1 point on the National Institutes of Health Stroke Scale [NIHSS] aphasia score) and global neurological improvement (gain of ⩾ 4 points on the NIHSS) were compared in minor strokes (NIHSS ⩽ 7), moderate strokes (NIHSS 8-15), and major strokes (NIH ⩾ 16). Sixty-nine of 243 stroke patients suffered from aphasia. Improvement of aphasia occurred in 7/16 minor strokes, 11/25 moderate strokes, and 7/28 severe strokes. Improvement of ⩾ 4 points on the NIHSS occurred in 3/16 minor strokes, 17/25 moderate strokes and 15/28 severe strokes. There is a significant (X(2)=4.073, p<0.05) dissociation of recovery of aphasia and that of other neurological deficits between minor versus severe strokes. This confirms the clinically suspected dissociation between a good early recovery from aphasia in minor strokes relative to recovery of other neurological deficits, as opposed to a better recovery from other neurological deficits than from aphasia in patients with severe strokes.