This scoping review of 76 randomized controlled trials (RCTs) of surgical prehabilitation identified 50 different outcomes measured using 184 outcome assessment tools. The majority of trials focused on abdominal or orthopaedic surgeries. Observer-reported outcomes were most common, with hospital length of stay being the most frequently reported. Performance outcomes, such as exercise capacity assessed by cardiopulmonary exercise testing, were reported in 80% of trials. Clinician-reported outcomes, including postoperative complications using the Clavien-Dindo classification, were reported in 78% of trials. Patient-reported outcomes, such as health-related quality of life using the SF-12 or SF-36 surveys, were reported in 76% of trials. Biomarker outcomes, such as inflammatory markers measured by C-reactive protein, were reported in 16% of trials. The review highlights significant heterogeneity in the reporting of outcomes and assessment tools across surgical prehabilitation trials. This heterogeneity limits the ability to pool data for meta-analyses and hinders the development of a standardized core outcome set. The study emphasizes the need for consensus on meaningful outcomes and appropriate assessment tools to improve the consistency and quality of prehabilitation research. The findings suggest that while traditional clinical outcomes like hospital length of stay and postoperative complications remain prevalent, patient-reported and performance outcomes are also increasingly important. The review underscores the importance of developing a core outcome set to harmonize outcome reporting and facilitate meta-analyses, ultimately guiding clinical practice and healthcare policies.This scoping review of 76 randomized controlled trials (RCTs) of surgical prehabilitation identified 50 different outcomes measured using 184 outcome assessment tools. The majority of trials focused on abdominal or orthopaedic surgeries. Observer-reported outcomes were most common, with hospital length of stay being the most frequently reported. Performance outcomes, such as exercise capacity assessed by cardiopulmonary exercise testing, were reported in 80% of trials. Clinician-reported outcomes, including postoperative complications using the Clavien-Dindo classification, were reported in 78% of trials. Patient-reported outcomes, such as health-related quality of life using the SF-12 or SF-36 surveys, were reported in 76% of trials. Biomarker outcomes, such as inflammatory markers measured by C-reactive protein, were reported in 16% of trials. The review highlights significant heterogeneity in the reporting of outcomes and assessment tools across surgical prehabilitation trials. This heterogeneity limits the ability to pool data for meta-analyses and hinders the development of a standardized core outcome set. The study emphasizes the need for consensus on meaningful outcomes and appropriate assessment tools to improve the consistency and quality of prehabilitation research. The findings suggest that while traditional clinical outcomes like hospital length of stay and postoperative complications remain prevalent, patient-reported and performance outcomes are also increasingly important. The review underscores the importance of developing a core outcome set to harmonize outcome reporting and facilitate meta-analyses, ultimately guiding clinical practice and healthcare policies.