Introduction: The reconciliation of medications is an important process that impacts on patient safety during the level of care transition, a moment with high discrepancy rates that can lead to adverse reactions. Objective: To analyze the results of medication reconciliation in order to identify discrepancies between the medical prescription and the medications previously used by the patient. Method: A descriptive, cross-sectional study was conducted between May and November 2017 (until the second fortnight of the month), with patients admitted to the cardiology department of the University Hospital of Brasília. Data was collected through interviews with patients, relatives and/or caregivers, and through consultation of the medical records. The reconciliation of medications was performed daily, from Monday to Friday, within 48 hours of the patient’s admission to the unit, through a medication reconciliation form prepared by the author. Results: 90 patients were included in the study and a total of 297 discrepancies were found, 267 (90%) being intentional and 30 (10%), unintentional. Among the unintentional discrepancies, the most frequent was omission of medication in use by the patient (56%). Of the intentional discrepancies, the dosage modifications were more common in 45% of the cases. Conclusion: The reconciliation of medications was a crucial clinical service for the identification and resolution of unintentional discrepancies between previously used medications and hospital medical prescription.