Objective.To describe the Italian Obstetric Surveillance System (ItOSS) investigating maternal death through incident case reporting and confidential enquiries.Methods. All maternal deaths occurred in any public and private health facility in 8 Italian regions covering 73% of national births have been notified to the ItOSS. Every incident case is confidentially reviewed to assess quality of care and establish the cause and avoidability of the death.Findings. A total of 106 maternal deaths among 1.455.545 new-borns have been notified to the surveillance system in 2013-17. Haemorrhage, sepsis and hypertensive disorders of pregnancy are the leading causes of direct maternal deaths due to obstetric causes.Conclusions. A maternal mortality surveillance system, including incidence reporting and confidential enquiries along with a retrospective analysis of administrative data sources, emerged as the best option for case ascertainment and for promoting avoidable maternal deaths.