This was a single center, retrospective cross-sectional study looking into the incidence and types of drug-related problems (DRPs) detected among elderly cancer patients receiving at least three long-term medications concurrent with IV chemotherapy, and the types of intervention taken to address these DRPs. This paper serves to elucidate the prevalence and risk of polypharmacy in our geriatric oncology population in an ambulatory care setting, to raise awareness on this growing issue and to encourage more resource allocation to address this healthcare phenomenon.