BACKGROUND: The inclusion of clinical frailty in the assessment of patients planned for major surgery has proven to be an independent predictor of outcome. Since approximately half of all patients in the UK diagnosed with oesophagogastric (OG) cancer are over 75 years of age, assessment of frailty may be important in selection for surgery. MATERIALS AND METHODS: This retrospective cohort study applied the Hospital Frailty Risk Score to data obtained from the NHS Secondary Uses Service electronic database for patients aged 75 years or older undergoing oesophagectomy and gastrectomy between April 2017 and March 2020. Descriptive statistics were performed to assess the effect of patient frailty on length of stay, 30-day readmission, and 30-day mortality rates. These outcomes were compared with those published by the National Oesophago-Gastric Cancer Audit. RESULTS: Over 90% of the 1775 patients identified according to the age and resection criteria exhibited some degree of frailty. The median length of stay and 30-day readmission rate increased as patient frailty increased following both oesophagectomy and gastrectomy, as did the 30-day mortality rate following gastrectomy. CONCLUSION: Frailty is a dynamic state and increasing age alone should not be a barrier to receiving the most appropriate treatment. Introducing standardized assessment of clinical frailty for patients with OG cancer to identify this cohort of patients earlier might enable targeted screening for frailty syndromes. This could facilitate the enhanced delivery of more holistic, frailty-attuned, approaches to person-centred care, and evidence-based treatment pathways for improved patient outcomes.