In a nationwide survey of Creutzfeldt-Jakob disease (CJD) in Japan, the point prevalence rate on June 1, 1978 in Fukuoka Prefecture and the estimated national prevalence rate were approximately one per one million population. The minimal period prevalence rate was 0.45 per one million population. The minimal annual incidence and the minimal annual mortality rate were 0.19 and 0.15 per one million population, respectively. The geographic distribution of CJD in Japan was uniform. Clinically, CJD affected the central nervous system diffusely and was rapidly fatal. No specific features were found in family, social, and past histories.