Background: Increasing age is associated with more medication errors in hospitalised patients. Patient engagement is a strategy to reduce medication harm. Aims: To measure older patients’ preferences for and reported medication safety behaviours, identify the relationship between preferred and reported medication safety behaviours and identify whether perceptions of medication safety behaviours differ between groups of young–old, middle–old and old–old patients (65–74 years, 75–84 years, and ≥ 85 years). Methods: A survey, which included the Inpatient Medication Safety Involvement Scale (IMSIS) was administered to 200 older patients from medical settings, at one hospital. Data were analysed using descriptive statistics, Spearman’s rho and the Kruskal–Wallis test. Results: Patients reported a desire to ask questions (59.5% n = 119) and check with healthcare professionals if they perceived that a medication was wrong (86.5% n = 173) or forgotten (87.0% n = 174). Patients did not have particular preferences, which differed from their experiences in terms of viewing the medication administration chart and self-administering medications. Preferred and reported behaviours correlated positively (r = 0.46–0.58, n = 200, p ≤ 0.001). Young-old patients preferred notifying healthcare professionals of perceived medication errors more than middle–old and old–old patients (p ≤ 0.05). Conclusions: Older patients may prefer verbal medication safety behaviours like asking questions and notifying healthcare professionals of medication errors, over viewing medication charts and self-administering medications. The young-old group wanted to identify perceived medication errors more than other age groups. Older patients are willing to engage in medication safety behaviours, and healthcare professionals and organisations need to embrace this engagement in an effort to reduce medication harm.