OBJECTIVES: To examine the relationships between urgent care activity and mortality among patients admitted to hospital on weekends compared to weekdays METHODS: A retrospective analysis was performed of all emergency acute care admissions in England between April 2009 and March 2011 using National Health Service Hospital Episode Statistics data. Hospital mortality among patients admitted on weekends as compared to weekdays was analysed using the following measures; (1) overall deaths; (2) deaths within and after three days of admission (3) deaths among patients with higher risk conditions and lower risk conditions. The higher risk conditions consisted of 103 Primary Diagnosis codes (ICD-10) which accounted for 74% of hospital deaths in England; the remaining codes were categorised as lower risk conditions. RESULTS: There were 10,221,500 emergency hospital admissions during the two-year study period; 23.8% of the patients were admitted on weekends. A total of 391,938 patients died in hospital. Weekend admission was associated with significantly higher mortality as compared to weekday admission (Odds Ratio 1.11, 95% CI 1.10-1.12). Mortality within three days of admission (early deaths) was also higher for patients admitted on weekends (OR 1.16, 95%CI (1.14-1.17) and this difference persisted for both higher and lower risks conditions. However, when early deaths were excluded from the analysis, mortality was not affected by weekend admission. CONCLUSIONS: As mortality after three days of admission was not affected by weekend admission, it is probable that the weekend admission effect on mortality is largely due to higher disease severity at admission on weekends rather than a consequence of shortfalls in quality of care on weekends as postulated in previous studies.