Plasmatic hyperviscosity is a known vascular risk factor which depends, among other parameters, upon total proteins, haematocrit value and fibrinogen. The aim of this study was to determine the relationship between these analytical haemorrological parameters and mortality and acute stroke sickness rate. We studied 216 patients with brain infarct and spontaneous intracerebral haemorrhage out of a sample of 256 acute stroke patients. We evaluated neurological affectation using the Canadian scale upon admission, on the seventh day and after three months. We determined plasmatic haemorrological factors (haematocrit, fibrinogen and total proteins) upon admission and again after one week and then at three months High fibrinogen levels in plasma were related to brain infarct mortality regardless of the cause of death.