The concept of death has evolved medically, legally and culturally since the introduction of life support technologies in the middle of the 20th century. The traditional cardiopulmonary and the new neurologically based brain death criterions of death are examined. We conclude that brain death, defined as total and irreversible loss of function of the whole brain, fulfills better "the permanent cessation of functioning of the organism as a whole" definition of death. Brain death diagnosis, based on standard neurologic clinical examination performed accurately, is unequivocal. Transplantation medicine, mostly based on organ donation of brain dead people, has become a routine and universally accepted therapeutic intervention nowadays, which benefits many people. Ethics foundations of organ transplantation are reviewed. Even though brain death and organ donation are widely accepted in medical, legal, religious and public opinion today, the whole society and medical community need to be further educated about these matters, so that unavoidable changes of traditional concepts might be better understood. Permanent education should be the best way to dissipate social fears and distrust towards organ donation and brain death.