Creutzfeldt-Jakob disease (CJD) exists in inherited, acquired (variant and iatrogenic), and spontaneous (sporadic) forms. Although iatrogenic and variant forms of CJD usually affect relatively young persons, all forms may affect elderly persons, especially sporadic CJD. Sporadic CJD is a rare cause of dementia among middle-aged and elderly persons, and typical cases are clinically fairly distinct from more common forms of neurodegenerative dementias. However, clinical diagnosis can be a challenge for those who are not experienced with the disease. Fortunately, certain investigations can be very helpful. Although many cases of CJD (especially sporadic CJD) are not thought to be acquired illnesses, there is still a potential for onward transmission, and certain precautions are necessary to protect public health.