Background Older adults (≥ 65 years) with cancer receiving palliative care often have other health conditions requiring multiple medications. Aim To describe and assess the appropriateness of prescribing for older adults with cancer in the last seven days of life in an inpatient palliative care setting. Method Retrospective observational study of medical records for 180 patients (60.6% male; median age: 74 years; range 65-94 years) over a two-year period. Medication appropriateness was assessed using: STOPPFrail, OncPal deprescribing guideline and criteria for identifying Potentially Inappropriate Prescribing in older adults with Cancer receiving Palliative Care (PIP-CPC). Results 94.5% of patients had at least one other health condition (median 3, IQR 2-5). The median number of medications increased from five (IQR 3-7) seven days before death, to 11 medications on the day of death (IQR 9-15). The prevalence of PIP varied depending on the tool used: STOPPFrail (version 1: 17.2%, version 2: 19.4%), OncPal (12.8%), PIP-CPC (30%). However, the retrospective nature of the study limited the applicability of the tools. Increasing number of medications had a statistically significant effect on risk of PIP across all tools (STOPPFrail (version 1: 1.29 (1.13-1.37), version 2: 1.30 (1.16-1.48)); OncPal 1.13 (1.01-1.27); PIP-CPC 0.70 (0.61-0.82)). Conclusion This study found that the number of medications prescribed to older adults with cancer increased as time to death approached, and the prevalence of PIP varied with the application of different tools. The study also highlights the difficulties of examining PIP in this patient cohort.