Blood and urine alcohol analyses were performed by gas chromatography, and drug analyses used gas chromatography, liquid chromatography, thin-layer chromatography, and ultraviolet spectrophotometry. Sixty-three percent of the driver fatalities had some alcohol in their blood streams. Fifty percent of the driver fatalities were at or above the legal intoxication level. Of the 1,158 fatalities tested for marijuana, 16.8 percent tested positively. More than 5 percent of fatalities had some level of drugs (either illicit or prescription) in their blood streams, notably diazepam, phenobarbital, methaqualone, and propoxyphene, all of which have some degree of central nervous system depressant action. Although the presence of alcohol or drugs in the blood of a fatality cannot be assumed to have caused the accident, numerous studies indicate that alcohol, marijuana, and certain drugs (especially the tranquilizers and the CNS depressants) impair the skills important to safe driving. Driving under the influence of marijuana is apparently a significant problem among young drivers. There was no significant difference in the presence of drug and alcohol between urban and rural fatalities. 4 tables and 8 references.