OBJECTIVE: To assess the association between favourable neurological outcome and hospital characteristics such as hospital volume and number of critical care centres (CCMCs) after out-of-hospital cardiac arrest (OHCA). METHODS: This retrospective, population-based observational study conducted in Osaka Prefecture, Japan included adult patients with OHCA, aged ≥18 years who were transported to acute care hospitals between January 2005 and December 2012. We divided acute care hospitals into CCMCs or non-CCMCs, the latter of which were divided into the following three groups according to the annual average number of transported OHCA cases: low-volume (≤10 cases), middle-volume (11-39 cases), and high-volume (≥40 cases) groups. Random effects logistic regression models, with hospital treated as a random effect, were used to assess factors potentially associated with a favourable neurological outcome. RESULTS: A total of 44,474 patients were eligible. The proportions of favourable neurological outcome from OHCA were 0.9% (31/3559) in the low-volume group, 1.2% (106/9171) in the middle-volume group, 1.6% (222/14,007) in the high-volume group, and 4.3% (766/17,737) in the CCMC group (P<0.001). In the multivariable analysis, transport to CCMCs was significantly associated with favourable neurological outcome, compared with transport to non-CCMCs (adjusted odds ratio 1.63; 95% confidence interval, 1.60-1.66). Among the non-CCMC group, there was no significant relationship between hospital volume and favourable neurological outcome. CONCLUSIONS: In this population, transport of OHCA patients to CCMCs led to significantly higher one-month survival rates with favourable neurological outcome from OHCA, whereas no significant association was noted among the hospitals with different volumes.