cancer often co-occurs with other chronic conditions, and despite the high prevalence of multimorbidity (mmb) in this group, conditions are often treated individually, resulting in multiple prescriptions. polypharmacy commonly defined as the use of five or more medications, is more common among people with mmb and is associated with a number of adverse outcomes (i.e., increased health service utilization and death). the literature sufficiently describes the occurrence and associated adverse outcomes among older adults; however, there are limited studies on this topic in younger adults. objectives: the aim of this current study is to examine polypharmacy and its impact among adults 18 years or older with cancer and other chronic diseases. specifically, it examines the prevalence of polypharmacy across age, sex, mmb level, and type of cancer. it also assesses the relationship between polypharmacy, high use of health services (i.e., emergency room visits, hospitalization) and death, while controlling for other factors.