OBJECTIVES Ethnicity has complex effects on health and the delivery of health care in part related to language and cultural barriers. This may be important in patients requiring emergency abdominal surgery where delays have profound impact on outcomes. The aim here was to test if variations in outcomes (e.g. in-hospital mortality) exist by ethnic group following emergency abdominal surgery. STUDY DESIGN Retrospective cohort study using population-level routinely collected administrative data from England (Hospital Episode Statistics). METHODS Adult patients undergoing emergency abdominal operations between April 2008 and March 2012 were identified. Operations were divided into: 'major', 'hepatobiliary' or 'appendectomy/minor'. The primary outcome was all cause in-hospital mortality. Univariable and multivariable analysis odds ratios (OR with 95% confidence intervals, CI) adjusting for selected factors were performed. RESULTS 359,917 patients were identified and 80.7% of patients were White British, 4.7% White (Other), 2.4% Afro-Caribbean, 1.6% Indian, 2.6% Chinese, 3.1% Asian (Other) and 4.9% not known, with crude in-hospital mortality rates of 4.4%, 3.1%, 2.0%, 2.6%, 1.6%, 1.7% and 5.17%, respectively. The majority of patients underwent appendectomy/minor (61.9%) compared to major (20.9%) or hepatobiliary (17.2%) operations (P < 0.001) with an in-hospital mortality of 1.7%, 11.5% and 3.9% respectively. Adjusted mortality was largely similar across ethnic groups except where ethnicity was not recorded (compared to White British patients following major surgery OR 2.05, 95% 1.82-2.31, P < 0.01, hepatobiliary surgery OR 2.78, 95% CI 2.31-3.36, P = 0.01 and appendectomy/minor surgery OR 1.78, 95% 1.52-2.08, P < 0.01). CONCLUSIONS Ethnicity is not associated with poorer outcomes following emergency abdominal surgery. However, ethnicity is not recorded in 5% of this cohort and this represents an important, yet un-definable, group with significantly poorer outcomes.