BACKGROUND: Little is known about the association between prehospital cardiopulmonary resuscitation duration for adults with out-of-hospital cardiac arrest and outcome by the location of arrests. This study aimed to investigate the association between prehospital cardiopulmonary resuscitation duration and one-month survival with favourable neurological outcome. METHODS: We analysed 276,391 adults aged 18 years and older with out-of-hospital cardiac arrest of medical origin before emergency medical service arrival. Prehospital cardiopulmonary resuscitation duration was defined as the time from emergency medical service-initiated cardiopulmonary resuscitation to prehospital return of spontaneous circulation or to hospital arrival. The primary outcome was one-month survival with favourable neurological outcome (cerebral performance category 1 or 2). The association between prehospital cardiopulmonary resuscitation duration and favourable neurological outcome was assessed using univariable and multivariable logistic regression analyses. RESULTS: The proportion of favourable neurological outcomes was 2.3% in total, 7.6% in public locations, 1.5% in residential locations and 0.7% in nursing homes (P < 0.001). In univariable and multivariable logistic regression analyses, longer prehospital cardiopulmonary resuscitation duration was associated with poor neurological outcome, regardless of arrest location (P for trend < 0.001). Patients with shockable rhythm in both public and residential locations had better neurological outcome than those in nursing homes at any time point, and residential and public locations had a similar neurological outcome tendency among patients with shockable rhythm. CONCLUSIONS: Longer prehospital cardiopulmonary resuscitation duration was independently associated with a lower proportion of patients with favourable neurological outcomes. Moreover, the association between prehospital cardiopulmonary resuscitation duration and neurological outcome differed according to the location of arrest and the first documented rhythm.