BackgroundOlder persons with polypharmacy are at increased risk of harm from medications. Therefore, it is important that physicians and nurses, together with the persons, evaluate medications to avoid hazardous polypharmacy. It remains unclear how healthcare professionals experience such evaluations. This study aimed to explore physicians and nurses experiences from evaluations of older persons medications, and their related actions to manage concerns related to the evaluations.MethodIndividual interview data from 29 physicians and nurses were collected and analysed according to the critical incident technique.ResultsThe medication evaluation for older persons was influenced by the working conditions (e.g. healthcare professionals clinical knowledge, experiences, and situational conditions) and working in partnership (e.g. cooperating around and with the older person). Actions taken to manage these evaluations were related to working with a plan (e.g. performing day-to-day work and planning for continued treatment) and collaborative problem-solving (e.g. finding a solution, involving the older person, and communicating with colleagues).ConclusionWorking conditions and cooperation with colleagues, the older persons and their formal or informal caregivers, emerged as important factors related to the medication evaluation. By adjusting their performance to variations in these conditions, healthcare professionals contributed to the resilience of the healthcare system by its capacity to prevent, notice and mitigate medication problems. Based on these findings, we hypothesize that a joint plan for continued treatment could facilitate such resilience, if it articulates what to observe, when to act, who should act and what actions to take in case of deviations from what is expected.