Background: Equipment-related incidents in the operating room (OR) can affect quality of care. In this study, the authors determined the occurrence and effects on the care process in a large teaching hospital. - Methods: During a 4-week period, OR nurses reported equipment-related incidents during surgery procedures in both locations of the hospital. The incidents were reported using a separate form for each incident. A structured analysis (PRISMA) was used to analyse incidents that resulted in serious delays (>15 min). - Results: Forms were returned for 911 out of 1580 surgeries (57.7%). In total, 148 incidents were registered, relating to a total of 29 h and 45 min of extra work. In addition, 12 h and 9 min of operational delay was registered. Most incidents involved instruments (46%) or medical devices (28%). 68% occurred during surgery and 32% during the preparation phase. No direct physical harm was reported, although indirect harm, like longer anaesthesia, did occur and can be defined as an adverse event. 10% of the incidents led to a delay of over 15 min. For these incidents, ‘management decisions’ (eg, inventory capacity, planning procedure) was the most encountered root cause. Only six out of the 148 incidents found corresponded with the blame-free reporting database. - Conclusions: Equipment-related incidents occurred frequently in the involved hospital sites (up to 15.9%) and resulted in some extra work and additional minutes of delay per event. Management decisions have considerable influence on the occurrence of equipment-related incidents. There was serious under-reporting of incidents.