Background: Medication related admissions (MRAs) account for a substantial amount of all hospital admissions and most MRAs are considered preventable. In order to reduce the amount of MRAs, comprehensive medication reviews performed by clinical pharmacists on hospitalised patients could be a viable strategy. To study the effect of these reviews on the incidence of MRAs, a method of assessing whether an admission is an MRA or not is required. Two such methods will be compared in this study. Aim: The aim of this study was to assess hospitalisations using AT-HARM10 and the OPERAM DRA Adjudication Guide (OPERAM tool) and compare the results. Method: The OPERAM tool and AT-HARM10 were used to assess hospitalisations.  Assessments yielding different results were discussed in a review panel and the reasons for the differences were determined. Cases where the assessments provided different results due to an error made by the assessor were changed. Trends in the reasons for deviation as well as statistics on the agreements of the tools were produced. Results: The initial agreements between the tools was 76%. After adjustment from the review panel discussion the agreement was 95%. A few cases where the OPERAM tool did not follow current evidence-based recommendations were identified. Discussion: Though the tools showed a high level of agreement, a few strengths and limitations of both designs could be identified. The main limitation of the OPERAM tool was the trigger tool which contained some outdated information while in AT-HARM10 the competence of the assessor could impact the results. Conclusion: Both tools showed a high level of agreement and seem to be a viable option for determining whether a hospital admission is possibly or unlikely to be an MRA.