Introduction: Termination of Resuscitation (TOR) rules have been designed to guide in-field termination decisions and reduce futile hospital transportations. The impact of such a rule may depend on regional infrastructure, arrest characteristics and pre-existent termination rates. Our region is characterized by high rates of bystander cardiopulmonary resuscitation (CPR), and Advanced Life Support (ALS) trained rescuers authorized to make termination decisions. We aim to investigate the actual in-field termination rates and the termination rates as recommended by the ALS-TOR rule. Furthermore, we studied factors associated with the actual termination decisions. Methods: Cohort of out-of-hospital cardiac arrest patients who were resuscitated in the Nijmegen area, the Netherlands (2008-2011). The ALS-TOR rule recommends termination in case all following criteria are met: unwitnessed arrest, no bystander CPR, no shock delivery, no return of spontaneous circulation (ROSC). Results: The observed percentage of in-field termination was 46% (275/598), while the ALS-TOR rule recommended termination in only 6% (35/588), owing to high percentages of witnessed arrests (73%) and bystander CPR (54%) in our region. Factors independently associated with the actual decisions to terminate resuscitation were absence of ROSC [aOR 35.6 (95% CI 18.3-69.3)], non-shockable initial rhythm [aOR 6.0 (95% CI 3.2-11.0)], unwitnessed arrest [aOR 2.7 (95% CI 1.4-5.2)], non-public arrest [aOR 2.5 (95% CI 1.2-5.0)] and longer EMS-response times [aOR 1.1 per minute increase (95% CI 1.0-1.2)]. Conclusions: Contrary to previous studies, implementation of the ALS-TOR rule in our region would have decreased termination rates from almost half to less than 10% due to the favourable arrest characteristics. In light of the prognosis after OHCA, this finding suggests that adherence to this set of criteria does not contribute to efficient triage in our population. Therefore it seems prudent to locally evaluate the utility of the ALS-TOR rule prior to implementation.