Caring for older adults with cancer receiving chemotherapy may present a number of challenges. Complications from chemotherapy are more common among older patients, and prevention and early detection of toxicities can improve treatment adherence, decrease costs, and improve treatment outcomes in this population. Over 12 months, 18 older adults with cancer (aged 65 years or older) participated in a quality-improvement project that provided telephone follow-up and intervention after chemotherapy administration; first-time chemotherapy recipients received telephone calls that followed assessment and referral guidelines over 10 days. Several characteristics of patients with increased toxicity were noted, including poor functional status, limited support at home, and significant comorbid disease. Recommendations for identifying patients at high risk are included so that services may be targeted for the most appropriate use of resources.