Abstract Background: Although comorbidities are identified in routine oncology practice, intervention plans for the coexisting needs of older people receiving chemotherapy are rarely made. This study evaluates the impact of geriatrician-delivered comprehensive geriatric assessment (CGA) interventions on chemotherapy toxicity and tolerance for older people with cancer. Methods: Comparative study of two cohorts of older patients (aged 70+ years) undergoing chemotherapy in a London Hospital.