Creutzfeldt-Jakob disease is a rare, fatal neurodegenerative disease characterised by spongiform encephalopathy and transmissibility. The majority of cases of the disease occur sporadically with no known causation. However, in a small number of well documented cases, the disease has developed following the use of cadaver-derived products, or after neurosurgical procedures with instruments previously used in intracranial operations on patients with Creutzfeldt-Jakob disease. Routine processing of this presumably contaminated material or the routine sterilisation of these instruments appears to have been inadequate in abolishing the viability of the agent causing the disease. Host genetic factors are also implicated in the susceptibility to iatrogenic disease.The variety of iatrogenic mechanisms by which Creutzfeldt-Jakob disease can be acquired emphasises the need for continued vigilance, and the careful assessment of benefit versus risk in any therapy based on human material, particularly when derived from the CNS.