Alcohol has been shown to confound the initial assessment of trauma victims, and cocaine is associated with numerous medical and anesthetic complications. A prospective study was performed to determine the prevalence of alcohol and illicit drug use in orthopedic trauma patients at an inner-city teaching hospital. All patients admitted to the orthopedic service during a 2-year period (January 1993 to December 1994) were prospectively studied. Patients < 14 years old were excluded. Blood alcohol levels were determined, and the urine was screened for cocaine, opiates, marijuana, barbiturates, amphetamines, benzodiazepines, and phencyclidine. Demographic data and a medical history were obtained. Seven hundred sixty-six patients met the study parameters. Of these, 628 (82%) had complete drug and alcohol screens available for review. The data were then sorted by diagnosis, mechanism of injury, type of injury (closed versus open), length of inpatient stay, age, sex, and race, and a statistical analysis was performed. The overall incidence of positive drug or alcohol tests was 56%. Twenty-four percent of patients tested positive for two or more drugs, and 9% for three or more. Alcohol (25%) was the most commonly detected drug, followed by cocaine (22%) and marijuana (21%). The highest incidence of drug use was found in males and in those ages 31-40 years. Hospital stay averaged 1.3 days longer in patients with positive screens. Patients with tibia fractures or open fractures, and those injuries sustained by gunshot, altercation, or pedestrian versus motor vehicle accident had the highest incidence of positive screens. These data show that drug-using patients have more severe orthopedic injuries (i.e., open fractures) and require longer hospitalizations. We conclude that drug and alcohol use is widespread in patients presenting with orthopedic injuries and we make recommendations regarding treatment of these patients. The majority of orthopedic trauma resources in this setting is devoted to treating intoxicated patients. Drug and alcohol use is a major social problem and may have an adverse effect on patient care.