Abstract Background Increasing age and frailty are associated with ‘futile’ emergency GI surgery and increased 30-day mortality after elective surgery. Consequently, older patients may be deemed “unfit” for major GI surgery, due to perceived risk of poor outcomes such as prolonged hospitalisation, poor functional recovery or mortality. Little is known about the baseline health characteristics and outcomes of the “unfit” group, with only a small number of studies performed on this patient group to date. This study aimed to comprehensively assess the baseline characteristics and functional trajectories of patients deemed “unfit” for major surgery using validated questionnaires. Methods This prospective, multicentre cohort study included patients aged 65 years or older with a diagnosis of elective or emergency GI pathology amenable to curative major GI surgery. Patients who underwent risk-adapted procedures or conservative management instead of curative major GI surgery formed the “unfit” cohort. Risk-adapted procedures included endoluminal stenting, defunctioning stomas and percutaneous tumour ablation. Baseline patient characteristics were recorded. Patients were followed up at 6 weeks, 3 months, and 6 months to assess survival, patient reported functional recovery using the World Health Organization Disability Assessment Schedule (WHO-DAS) questionnaire and quality of life using EQ-5D-5L. Results 19 patients formed the “unfit” cohort. 10 patients presented electively and 9 presented as an emergency. Within the elective group 30% were classified as frail and 20% required carers, in comparison to 89% and 56% respectively in the emergency group. Baseline WHODAS indicated higher patient reported disability in the emergency group. 6-month mortality was 40% in the elective group and 44% in the emergency group. At 6 weeks, functional status declined in both the elective and emergency groups. Only small numbers of patients completed follow-up at 3 and 6 months due to death prior to follow-up. Conclusions This study comprehensively assessed baseline functional status and quality of life in elective and emergency patients who were “unfit” for major GI surgery. The study found high rates of baseline frailty and functional disability, particularly amongst those who presented via emergency pathways. Over half of patients were alive at 6 months, but with high levels of functional impairment, suggesting that these patients may benefit from early involvement from geriatric and palliative care specialists. Further research is needed to improve outcomes in this understudied surgical population.