OBJECTIVES: The PREDICT study aimed to determine how the COVID-19 pandemic affected surgical services and surgical patients and to identify predictors of outcomes in this cohort. BACKGROUND: High mortality rates were reported for surgical patients with COVID-19 in the early stages of the pandemic. However, the indirect impact of the pandemic on this cohort is not understood, and risk predictors are yet to be identified. METHODS: PREDICT is an international longitudinal cohort study comprising surgical patients presenting to hospital between March and August 2020, conducted alongside a survey of staff redeployment and departmental restructuring. A subgroup analysis of 3176 adult emergency patients, recruited by 55 teams across 18 countries is presented. RESULTS: Among adult emergency surgical patients, all-cause in-hospital mortality (IHM) was 3 6%, compared to 15 5% for those with COVID-19. However, only 14 1% received a COVID-19 test on admission in March, increasing to 76 5% by July.Higher Clinical Frailty Scale scores (CFS >7 aOR 18 87), ASA grade above 2 (aOR 4 29), and COVID-19 infection (aOR 5 12) were independently associated with significantly increased IHM.The peak months of the first wave were independently associated with significantly higher IHM (March aOR 4 34; April aOR 4 25; May aOR 3 97), compared to non-peak months.During the study, UK operating theatre capacity decreased by a mean of 63 6% with a concomitant 27 3% reduction in surgical staffing. CONCLUSION: The first wave of the COVID-19 pandemic significantly impacted surgical patients, both directly through co-morbid infection and indirectly as shown by increasing mortality in peak months, irrespective of COVID-19 status.Higher CFS scores and ASA grades strongly predict outcomes in surgical patients and are an important risk assessment tool during the pandemic.