The importance of medical admissions units (MAU) has been emphasised by the royal colleges and the Society for Acute Medicine. This study looked at the time to treatment of four common medical conditions before and after the establishment of a dedicated MAU. Before the development of the MAU, treatment given in the emergency department (ED; median 111 minutes) was significantly quicker than on the admitting general medical ward (median 262 minutes, p<0.001). Following the establishment of the MAU, treatment given in the ED (median 70 minutes) remained significantly quicker than on the MAU (median 180 minutes, p<0.05). Treatment was given significantly quicker on the MAU compared with the antecedent admitting medical wards (p<0.05). In addition, more patients were treated within protocol-driven time guidelines. In summary, the establishment of a MAU significantly improved time to treatment, compared with admitting directly to general medical wards. This has implications for patients who are boarded directly to medical wards when the MAU is at full capacity.