A double-blind, randomized and placebo-controlled trial was conducted on 110 Chinese patients with ischaemic stroke who were stratified into 2 subtypes (cortical and lacunar infarcts) according to their clinical and CT findings. Treatment was started within 36-48 hours after the stroke onset. Pentoxifylline was administered intravenously in a dose of 600 mg daily for 5 days, together with oral aspirin 150 mg daily. Neurological deficits were scored on admission and at one week. Demographic data were comparable between the treatment and placebo groups. For cortical infarcts, there were significantly more patients in the placebo group who deteriorated and died than in the treatment group (p < 0.02). As for the lacunar infarcts, there was no difference between groups in the numbers of patients who improved or deteriorated. Our study shows that the positive effect of pentoxifylline can be demonstrated only in patients with cortical infarction. Early deterioration and mortality were significantly decreased in these patients. The clinical course of lacunar infarction was not affected by pentoxifylline. It is not clear whether aspirin may potentiate the antiplatelet function of pentoxifylline and contribute to its temporary clinical efficacy in this way.