Purpose: Emergency groin hernia is an understudied research field despite its severity requiring emergency surgery associated with high postoperative morbidity and mortality rates. Therefore, this study aimed to investigate the characteristics of patients, hernias, and surgical repairs, as well as complication rates following emergency groin hernia repair. Methods: Nationwide cohort study based on prospectively collected data obtained from the Danish Hernia Database and person-level linked to the Danish National Patient Registry. We included all adult patients undergoing an emergency groin hernia repair for inguinal- and/or femoral hernias registered in the Danish Hernia Database between January 1, 1998, and December 31, 2020. Primary outcomes were 30- and 90-day mortality, 30- and 90-day readmissions, and reoperations for recurrence. Outcomes were presented as crude numbers, odds ratios for mortality and readmission, and hazard ratios for reoperation. Results: We included 9741 patients in the study. Within 30 days of surgery, 510 (6%) deaths and 1800 (23%) readmissions were recorded. During a median follow-up of 5 years, 537 (6%) reoperations for recurrence were performed. Multivariate analyses showed that mortality and readmission rates were influenced by increasing age, comorbidity, and bowel resection. Cumulative and adjusted reoperation rates were lower for mesh than non-mesh repairs. Moreover, mortality rates have improved over time, whereas readmission rates have increased over time. Conclusions: Complication and mortality rates after emergency groin hernia repair remain high. This study underlines the importance of a timely repair in incarcerated hernias to avoid contaminated surgical fields and the need for bowel resection.