AIMS:to report the incidence, characteristics, and outcome of in-hospital cardiac arrest (IHCA) in a large Italian region. SETTING:all hospitals participating in the IHCA Registry Initiative of Piedmont. METHODS:observational cohort study in adult (>18year old) inpatients resuscitated from IHCA during three consecutive years (2012-2014). The main outcome measures were IHCA incidence and survival to hospital discharge. RESULTS:A total of1539 arrests in adult inpatients were recorded in the study period, yielding an overall incidence of 1.51 arrests/1000 admissions. The incidence was highest at day 1 after hospital admission and in the morning hours, with a peak at 9.00 a.m. Median age was 77 (interquartile range 68-83) years. The presenting rhythm was ventricular fibrillation/pulseless ventricular tachycardia in 291/1539 (18.9%) cases. A total of 549/1539 (35.7%) patients achieved recovery of spontaneous circulation (ROSC) and 228/1539(14.8%) survived hospital discharge, with 207 (90.8%) of the latter having good neurological outcome (Cerebral Performance Categories [CPC] 1 or 2).After adjustment for major confounders, a pre-arrest CPC=1, a cardiac cause of arrest, a shockable presenting rhythm, and a shorter duration of resuscitation were independently associated with a higher likelihood of survival to discharge. CONCLUSIONS:in this Italian registry the incidence of IHCA and its circadian distribution were comparable to those in the NCAA registry in the UK. Patients were older and had a lower ROSC rate than these observed in other large IHCA registries, but post-ROSC survival rate and factors affecting survival to discharge were similar.