This retrospective analysis of data from 89,658 patients who were admitted for one of a defined set of surgical procedures at NZ public hospitals between 2002 and 2008 compared the quality of hospital care for NZ Māori and NZ European adult patients, using the rate of unplanned readmission or death within 30 days of discharge as an indicator of quality. Covariate-adjusted logistic regression analysis revealed that NZ Māori had 16% higher odds of readmission or death compared with NZ European patients. Readmission or death was also associated with being female (OR 1.09), older age (OR 1.33; for >79 years compared with 18–39 years), higher comorbidity (OR 2.08; for Charlson score 3+ compared with 0) and higher hospital volume (OR 0.81; for lowest volume compared with highest).