Although the number of centenarians has been rapidly increasing in industrialized countries, no clinical studies evaluated their characteristics and outcomes from out-of-hospital cardiac arrests (OHCAs). This nationwide, population-based, observation of the whole population of Japan enrolled consecutive OHCA centenarians with resuscitation attempts before emergency medical service arrival from 2005 to 2013. The primary outcome measure was 1-month survival from OHCAs. The multivariate logistic regression model was used to assess factors associated with 1-month survival in this population. Among a total of 4,937 OHCA centenarians before emergency medical service arrival, the numbers of those with OHCAs increased from 70 in 2005 to 136 in 2013 in men and from 227 in 2005 to 587 in 2013 in women. Women accounted for 80.3%. Ventricular fibrillation (VF) as first documented rhythm was 2.5%. The proportions of victims receiving bystander cardiopulmonary resuscitation were 64.2%. The proportion of 1-month survival from OHCAs in centenarians was only 1.1%. In a multivariate analysis, age was not associated with 1-month survival from OHCAs (adjusted odds ratio [OR] for one increment of age 1.01; 95% confidence interval [CI] 0.87 to 1.18). Witness by a bystander (adjusted OR 3.45; 95% CI 1.88 to 6.31) and VF as first documented rhythm (adjusted OR 5.49; 95% CI 2.24 to 13.43) were significant positive predictors for 1-month survival. Cardiac origin was significantly poor in 1-month survival compared with noncardiac origin (adjusted OR 0.37; 95% CI 0.21 to 0.64). In conclusion, survival from OHCAs in centenarians was very poor, but witness by a bystander and VF as first documented rhythm were associated with improved survival.