The database includes 492 cases that occurred over a period of approximately 3 1/2 years and comprises a majority of fatalities and related driving accidents, as well as all the drug impaired driving cases. Blood analysis for drugs was conducted in all of the cases. There were 173 impaired driving cases. These cases should reflect the trend of drug involvement, since the database contains all cases where blood analysis occurred (or admitted drug use). Single drug occurrence in a case was most common, followed by a single drug and alcohol, and then other drug and alcohol combinations. The most common drugs or drug groups in impaired-driving cases were THC, benzodiazepines (diazepam), narcotics (codeine), cocaine, and barbiturates. The occurrence of THC and codeine in impaired-driving cases has shown a dramatic increase since the initial data were first collected and entered in the database in 1985. The increase of THC may be due in part to an improved ability of forensic laboratories to detect low concentrations in small-volume blood samples; the observed cocaine increase is likely due to a general increase in drug abuse in Canadian society. The concurrent use of alcohol with THC is common in persons arrested for impaired driving. It is more common to encounter cocaine alone, without alcohol. For cases that involved codeine or butalbital, the use of alcohol was also less common. 4 tables and 4 references