In 1987 the Swedish Dental Act was amended to allow Swedish dentists who have undergone a specific accreditation course to administer intra-venous sedation. Midazolam is a benzodiazepin derivate with express sedative and hypnotic qualities, powerful amnesia, a short half-life time and few secondary effects. From 1989-1994 midazolam intravenous conscious sedation (ICS) was administered in 372 cases in the Department of Oral and Maxillofacial Surgery, County Hospital, Falun. This study presents data on the 298 patients. Although surgical removal of impacted wisdom teeth predominated, implant surgery, reduction of fractures and correction of anomalies were also carried out. Supplementary sedative premedication was rarely used. Most patients were treated under local anaesthesia. The mean dosage was 10.45 mg (range 1.25-40 mg). Mean dosage/kg was 0.15 mg (range 0.03-0.50 mg). The average duration of anaesthesia was 50 minutes. The average recovery time was 94 minutes. Three hundred and sixty-nine of 372 planned treatments were completed. No serious complications occurred. The patients were co-operative during surgery and were satisfied with the treatment. Compared with full anaesthesia this method required less resources and is a valuable complement in management of anxious patients undergoing oral surgery.