Purpose: An increasing number of older patients are undergoing emergency laparotomy (EL). Frailty is thought to contribute to adverse outcomes in this group. The best method to assess frailty - and impacts on long-term mortality and other important functional outcomes for older EL patients have not been fully explored. Methodology: A prospective multicentre study of older EL patients was conducted across four hospital sites in New Zealand from August 2017 - September 2022. The Clinical Frailty Scale (CFS) was used to measure frailty - defined as a CFS of ≥ 5. Primary outcomes were thirty-day and one-year mortality. Secondary outcomes were post-operative morbidity, admission for rehabilitation, and increased care level on discharge. A multivariate logistic regression analysis was conducted, adjusting for age, sex and ethnicity. Results: 629 participants were included. Frailty prevalence was 14.6%. Frail participants demonstrated higher thirty-day and one-year mortality– 20.7% and 39.1%. Following adjustment, frailty was directly associated with a significantly increased risk of short- and long-term mortality (30-day aRR 2.6, 95% CI 1.5, 4.3, p =<0.001, 1-year aRR 2.0, 95% CI 1.5, 2.8, p <0.001). Frailty was correlated with a 2-fold increased risk of admission for rehabilitation and propensity of being discharged to an increased level of care, complications and readmission within 30 days. Conclusion: Frailty was associated with increased risk of post-operative mortality up to one-year and other functional outcomes for older patients undergoing EL. Identification of frailty in older EL patients aids in patient centred decision-making which may lead to improvement in outcomes.