Objectives To compare rates and trends in hospital admissions due to medication misadventure for older adults (≥65 years) with and without dementia. Methods A retrospective analysis of hospital admissions that occurred between 2012 and 2016, for medication misadventures among older adults living in regional Australia. Results Medication misadventures contributed to 10 555 (4.6%) of the total 228 165 admissions for older adults over the study period. Among these admissions, older adults with dementia were three times more likely to be hospitalised with medication misadventures (14.0%), than their non‐dementia counterparts (4.2%). Medication misadventures relating to “anticoagulants” and “opioids/related analgesics” accounted for the majority of admissions (24.3% dementia vs 30.7% non‐dementia). Conclusions This study highlights that the proportion of older adults hospitalised for a medication misadventure is much higher among those with dementia, than those without dementia. Strategies should target older adults, and especially those with dementia, to reduce medication‐related harm and improve patient safety.