Abstract Aim The evidence base for statements about risk factors, morbidity and mortality for emergency hernia repair is mostly low quality. The aim of this study is to elucidate risk factors for the development of incarcerated hernia and outcome after adult emergency hernia repair using data from the Swedish Hernia Register (SHR). Material and Methods Data in this observational study were extracted from the SHR. It included registered cases between January 1, 2009 and December 31, 2019. Maximal follow-up was until December 31, 2020. Demographic data were analysed descriptively, risk analyses were performed using multivariate- and Cox-regression models. Results A total of 164.844 cases could be included after application of the in- and exclusion criteria. Women [odds ratio (OR) 1.42 99%CI 1.32–1.51], patients with lateral hernia [OR 1.54, 99%CI 1.47–1.61], femoral hernia [OR 14.63, 99%CI 13.32–16.06] and hernia recurrence [OR 2.46, 99%CI 2.33–2.60] were at higher risk of developing an incarcerated hernia. The highest strangulation risk was seen among women [OR 2.36, 99%CI 1.91–2.90], femoral hernia [OR 7.00, 99%CI 5.40–9.11] and recurrent hernia [1.90, 99%CI 1.54–2.33]. Patients with hernia incarceration or strangulation suffer significantly more frequent from postoperative complications [16.7% and 40.9% respectively, both p < 0.001]. Conclusions The data demonstrate that certain risks groups exist, which are prone to suffer from hernia incarceration and strangulation. These at risk patients should be prioritized, especially during the reorganisation of services to cope with the massive surgical backlog in the aftermath of the COVID-19 pandemic.