In the era of hyper-ageing, Creutzfeldt-Jakob disease (CJD) can become more prevalent as an important cause of dementia. This study aimed to evaluate the trends in crude and age-adjusted CJD-associated mortality and incidence rates in Japan using national vital statistics data on CJD-associated deaths among individuals aged over 50 years, as well as the government-funded nationwide CJD surveillance data (pertaining to the years 2005-2014) in Japan. The data were analysed using the Joinpoint Regression Program to estimate the long-term trends and average annual percentage changes (AAPCs). Overall, the AAPCs of age-adjusted CJD-associated mortality rates rose significantly over the study period (3.2%; 95% confidence interval [CI] 1.4-5.1%). The AAPC of the age-adjusted incidence rates also increased (overall 6.4%; 95% CI 4.7-8.1%). The CJD-associated increases in the mortality and incidence rates were especially prominent among adults over the age of 70 years. Given this trend in aging of population, the disease burden of CJD will continue to increase in severity. Our findings thus recommend that policymakers be aware of the importance of CJD and focus on preparing to address the increasing prevalence of dementia.