The clinico-tomographic correlations in 30 patients hospitalized for primary thalamic hemorrhage were studied. Arterial hypertension, observed in 90% of patients, represented the most important risk factor. Twenty-six subjects showed a sensory-motor hemisyndrome contralaterally to the lesion, nineteen showed alteration in level of consciousness from confusion to stupor and coma. Twelve subjects had poorly reactive pupils and eleven speech disturbances with involvement of the left thalamus. Seven patients died following hemorrhage; all subjects presented ventricular bleeding, severe disturbance of consciousness and arterial hypertension. On admission to hospital impairment of consciousness was the most significant unfavourable prognostic factor.