Hospital stays are often associated with medication changes, which may lead to drug-related problems (DRPs). Medication reconciliation and medication reviews are strategies to detect and resolve DRPs.; A descriptive cohort study was conducted using DRPs collected during routine pharmacist-led medication reconciliation and medication reviews in the hospital's community pharmacy at discharge (Zug Cantonal Hospital, Switzerland). In a simulation experiment, we retrospectively analysed the detection and resolution possibilities of these DRPs and their dependency on different information sources.; Overall, 6,087 prescriptions were filled in the hospital's community pharmacy (between June 2016 and May 2019). Among 1,352 prescriptions (with ≥ 1 documented DRP) a total of 1,876 DRPs were detected. The retrospective assessment showed that 1,115 DRPs could have been detected by performing simple medication reviews (based on the discharge prescription and the medication history), whereas in the remaining cases, additional clinical and/or patient-specific information would have been needed. In 944 (84.7 %) DRPs, which are detectable by simple medication reviews, the pharmacist would need to consult the prescriber for resolution.; The detection of DRPs is strongly influenced by the information available. These results support models with pre-discharge medication reconciliation and pharmacist-led medication review procedures enabling both comprehensive detection and facilitated resolution of DRPs.