The majority of European countries have published recommendations for the diagnosis of brain death as a necessary prerequisite for organ donation. The concept of brain death as defining the death of the individual is accepted in all European countries; however, the guidelines for determining the total and irreversible loss of all brain functions differ somewhat in the various countries. While the clinical examination and documentation of the clinical signs of brain death are very uniform, there are significant differences in the guidelines for using technical confirmatory tests to corroborate the clinical signs. These range from rejecting all technical tests to accepting of multiple neurophysiological tests alone or in combination. The present study examined the similarities and differences in current concepts of brain death in the various European countries and their recommendations for the diagnosis of brain death. The diagnosis of brain death is based on a number of prerequisites, on the clinical diagnosis of deep coma, loss of all brainstem reflexes, and the demonstration of apnea. Neurophysiological tests are recommended by a number of national professional societies as confirmatory tests to confirm the clinical diagnosis of brain death and shorten otherwise necessary waiting periods of 6-12 h. Most brain death codes allow the use of electroencephalography, which must demonstrate electrocortical silence over a certain period. Evoked cerebral potentials can demonstrate the successive loss of activity of various afferent pathways and are accepted in some countries as a confirmatory test. Other neurophysiological tests which demonstrate the loss of cerebral perfusion can be implemented. Brain scintigraphy can confirm the loss of isotope uptake into the brain. Doppler sonography also demonstrates cessation of brain perfusion. Cerebral panangiography may also be used to demonstrate the loss of brain perfusion but is less desirable since it might endanger the patient.