Background: Early cardiopulmonary resuscitation (CPR) and early defibrillation are critical to survival from out-of-hospital cardiac arrest (OHCA). However, few studies have investigated the relationship between time interval from collapse to return of spontaneous circulation (ROSC) and neurologically intact survival. Methods: From the All-Japan OHCA Utstein Registry between 2005 and 2015, we enrolled adult patients achieving prehospital ROSC after witnessed OHCA, inclusive of arrest after emergency medical service responder arrival. The study patients were divided into two groups according to initial cardiac arrest rhythm (shockable versus non-shockable). The collapse-to-ROSC interval was calculated as the time interval from collapse to first achievement of prehospital ROSC. The primary endpoint was 30-day favorable neurological outcome after OHCA. Results: A total of 69,208 adult patients achieving prehospital ROSC after witnessed OHCA were enrolled; 23,017(33.3%) the shockable arrest group and 46,191 (66.7%) the non-shockable arrest group. The shockable arrest group compared with the non-shockable arrest group had significantly shorter collapse-to-ROSC interval (16±10 min vs. 20±13 min, P<0.001) and significantly higher frequency of the favorable neurological outcome (54.9% vs. 15.3%, P<0.001). Frequencies of the favorable neurological outcome after shockable OHCA decreased to 1.2% to 1.5% with every minute that the collapse-to-ROSC interval was delayed (78% at 1 minute of collapse, 68% at 10 minutes, 44% at 20 minutes, 34% at 30 minutes, 16% at 40 minutes, 4% at 50 minutes and 0% at 60 minutes, respectively, P<0.001), and those after non-shockable OHCA decreased to 0.8% to 1.8% with every minute that the collapse-to-ROSC interval was delayed (40% at 1 minute of collapse, 26% at 10 minutes, 11% at 20 minutes, 5% at 30 minutes, 2% at 40 minutes, 0% at 50 minutes and 0% at 60 minutes, respectively, P<0.001). Conclusions: Termination of the collapse-to-ROSC interval to achieve neurologically intact survival after witnessed OHCA was 50 minutes or longer irrespective of initial cardiac arrest rhythm (shockable versus non-shockable), although the neurologically intact survival rate was difference between the two groups.