There is ample evidence that the poststroke confusion syndrome or delirium is a manifestation of cholinergic deficit. Given this conception, we conducted a controlled study of efficacy and safety of acetylcholinesterase inhibitor rivastigmine in patients developed a delirium in the acute phase of ischemic stroke. The study included 224 consecutive stroke patients: 68 patients developed a delirium in the acute phase of disease. Severity of delirium was scored with the Delirium Rating Scale (DRS). A main group included 21 patients with delirium treated with rivastigmine in individually tailored doses. A control group included 47 patients with delirium who received only vascular and anticoagulant treatment, i.e. haloperidol. Cognitive functions were tested 3 and 6 months after stroke with the MMSE, the FAB, the Luria 10 point verbal test. The Zarit Burden Interview (ZBI) was used after 3 and 6 months to measure caregiver burden. In patients treated with rivastigmine, the delirium phase was significantly shorter (p<0,001) compared to the control group. In patients without delirium in the acute phase of stroke, the results of neuropsychological study were better (p<0,001) than in patients with delirium. Total ZBI scores were more favorable in the rivastigmine group than in the control one (p<0,05). To the end of the study, 5 patients died in the rivastigmine group, 17 patients in the control group and 3 patients in the group without delirium. Rivastigmine was safe in the acute phase of stroke patients even after the rapid titration.