Ischaemic penumbra is defined as the area of brain tissue that maintains some blood flow following ischaemic accident. This zone may be rescued by both neuroprotection and arterial revascularization. Early thrombolysis has been used with encouraging results since 1995 in several trials testing both streptokinase and recombinant tissue plasminogen activator (r-TPA): the r-TPA results are definitely more positive than those of streptokinase, despite an increased incidence of symptomatic haemorrhagic transformation, r-TPA significantly reducing death or dependency at the end of follow-up. Despite the fact that some experimental periods of application of these therapeutic strategies demonstrated real cost-effective benefits, only 1% of patients reaching hospital in time for thrombolysis are currently treated. This is because the profile of patients at risk of haemorrhagic transformation, which is definitely the most feared side-effect of thrombolysis in stroke, is yet to be clearly defined. Extended computerized tomography (CT) signs of the index stroke have been repeatedly indicated as reliable predictors of haemorrhagic transformation even if currently there are significant discrepancies in the criteria adopted by different researchers to define early CT signs. Based on experimental ischaemia, strategies for protecting the basal lamina during thrombolysis are suggested: neuroprotection is the second approach to stroke therapy; pharmacological reperfusion and brain protection are probably mutually dependent.