This article describes the potential contribution of alcohol and illicit drugs to increased risk of road accidents in Italy. Blood and urine samples were taken from patients admitted to five Emergency Rooms (ER) in metropolitan Florence, Italy, due to road traffic accidents within 3 hours of the accident. Seven hundred and thirtyfive patients were tested to determine if alcohol and illicit drugs (amphetamines, opiates, cocaine, methadone, and cannabis) were present in urine and blood. Approximately 22% of patients were positive for at least one substance at night-time