BACKGROUND:The term 'emergency open abdominal surgery' covers a range of common procedures with high complication and mortality risks; however, previous studies have not included descriptive analyses of the patients undergoing the procedures. The aim of this study is to present a nationwide description of all patients who undergo an emergency bowel resection, ostomy placement or drainage involving laparotomy at Danish hospitals and to report the 30- and 365-day mortality risks. METHOD:We identified all of the patients in the Danish National Patient Register aged 18 + who underwent emergency open abdominal surgery in the form of a laparotomy during the period 2003-14. Using Poisson and logistic regression models, we analyzed incidence rates and mortality risk. RESULT:The sample consisted of 15,680 patients, with an overall open abdominal surgery incidence rate of 30.4 cases per 100,000 person-years. The 30-day mortality risk was 19.3% for both sexes, and increased with age (at 80-89, mortality risk was 39.4% for males and 34.5% for females). The 30-day mortality risk fell by 5.4% during the study period, from 22.2% to 16.7%. CONCLUSION:Open abdominal surgery is a common, high-risk procedure with a high incidence rate and mortality risk, especially for elderly patients. The incidence rate and mortality risk fell during the period studied. In Denmark, there is no standard post-discharge care program for patients who undergo emergency laparotomies. Our results support the need to investigate standardized post-operative follow-up and rehabilitation plans to reduce mortality.