Background Emergency department (ED) pharmacists reduce medication errors and improve quality of medication use. Patient perceptions and experiences with ED pharmacists have not been studied. The aim of this study was to explore patients' perceptions of and experiences with medication-related activities in the ED, with and without an ED pharmacist present. Methods We conducted 24 semistructured individual interviews with patients admitted to one ED in Norway, 12 before and 12 during an intervention, where pharmacists performed medication-related tasks close to patients and in collaboration with ED staff. Interviews were transcribed and analysed applying thematic analysis. Results From our five developed themes, we identified that: (1) Our informants had low awareness and few expectations of the ED pharmacist, both with and without the pharmacist present. However, they were positive to the ED pharmacist. (2) Our informants expressed a variation of trust in the healthcare system, healthcare professionals and electronic systems, though the majority expressed a high level of trust. They believed that their medication list was automatically updated and assumed to get the correct medication. (3) Some informants felt responsible to have an overview of their medication use, while others expressed low interest in taking responsibility regarding their medication. (4) Some informants did not want involvement from healthcare professionals in medication administration, while others expressed no problems with giving up control. (5) Medication information was important for all informants to feel confident in medication use, but the need for information differed. Conclusion Despite being positive to pharmacists, it did not seem important to our informants who performed the medication-related tasks, as long as they received the help they needed. The degree of trust, responsibility, control and information varied among ED patients. These dimensions can be applied by healthcare professionals to tailor medication-related activities to patients' individual needs.