'Cell therapy' is a long-standing quack remedy used in Germany and adjacent countries. Organ extracts from fetal or young animals, fresh or lyophilized, are injected, with the intention of achieving 'cure' or at least 'treatment' of postulated organ deficiencies or failures. In Germany and in Australia 'cell therapy' has been administered in Down syndrome, cancer and for traumatic and other brain injuries. The preparation is banned in Germany, and can be lawfully imported into Australia only with express Ministerial permission. Even so its illicit use has been widespread. Morbidity and mortality have been reported since 1956, mostly in the German literature. There is a finite risk of infection with slow viruses of animal origin. This possibility should be considered in otherwise unexplained spongiform encephalopathy or leuco-encephalitis. Legal problems are considerable when quack practitioners (medically qualified or otherwise) administer such a preparation to children or legally incompetent adults.