Delirium is a common complication of stroke worsening its prognosis. In this work we have analyzed the frequency of delirium and factors, predisposing to its development in the population of Russian patients in hyperacute phase of stroke. Twenty two of 96 (around 23%) recruited patients revealed symptoms of delirium according to DSM-IV criteria. Patients of older age, those with severe stroke, with prominent chronic cerebral changes on brain CAT scan, with fever, those with urine catheter and with positive snout reflex were more likely to develop delirium. Severity of posterior leucoareosis was the only independent predictor of delirium according to multivariate analysis.