Clinical decision units (CDUs) are areas within an emergency department (ED) providing care for the patient who may benefit from an extended observation period, usually for a maximum of twenty-four hours. A retrospective patient record audit was performed to determine the characteristics of patients admitted to the Cork University Hospital (CUH) CDU over 12 months. The average length of stay of a patient in the CDU was 29 hours. The most common diagnoses admitted to the CDU were chest pain (9.5%) and headache (7.2%). The research implies that the CDU provided a means for CUH to save approximately €2 million annually.