Methods and Results:This study analyzed a total of 4,625 AMI patients enrolled in the Osaka Acute Coronary Insufficiency Study registry from 1998 to 2014. The prehospital time delay was defined as the time interval from the onset of initial symptoms to hospital arrival time ≥2 h. Among eligible patients, 2,927 (63.3%) had a prehospital time ≥2 h. In multivariable analyses, age 65–79 years (adjusted odds ratio [AOR] 1.19, 95% confidence interval [CI] 1.02–1.39), age ≥80 years (AOR 1.42, 95% CI 1.13–1.79), diabetes mellitus (AOR 1.33, 95% CI 1.16–1.52), and onset time of 0:00–5:59 h (AOR 1.63, 95% CI 1.37–1.95) were positively associated with prehospital time ≥2 h, whereas smoking (AOR 0.78, 95% CI 0.68–0.90) and ambulance use (AOR 0.37, 95% CI 0.32-0.43) were negatively associated with prehospital time ≥2 h.