Vegetative disturbances were observed in 88 out of 102 patients, 86%, after a primary brain lesion during onset of brain death. Tachycardia was most common in 64%, hypotonia below 80 mm Hg and hypertonia above 170 mm Hg were present in about half of all cases. Hyperthermia above 40 degrees C was noted in 25%, hypothermia below 36 degrees C was observed in 31%. The kind of underlying brain lesion had no regular influence on the vegetative disturbances. In 5 out of 6 younger patients these disturbances were less pronounced.