This study examined the Consumer Product Safety Commission (CPSC) Death Certificate file to identify frequency and rate of accidental CO poisoning deaths associated with exhaust gases of stationary vehicles in enclosed areas. A comprehensive search was then made to determine whether or not there was an increase in such deaths with the introduction of “smart keys” (available as standard equipment beginning in 2004).For 2000-2011 CY, the CPSC file contained 4,760 death certificate records for ICD-10 code X47 (accidental poisoning by exposure to other gases and vapors). The manual review of narratives for these records covered 2004-2011 and found 1,553 CO poisoning deaths associated with vehicle exhaust, including 748 for enclosed areas.For these 748 incidents, information on victim and location was then identified, and an exhaustive effort was undertaken to determine whether the vehicles involved were equipped with rotary or smart keys. Researchers contacted multiple agencies (e.g., state health departments, fire and police departments, news agencies, rescue services, coroner's offices) for information that would identify make, model and year. Such information was identified for about 260 deaths.The data shows that the rate of CO poisoning deaths from vehicle exhaust per 10 million US population is not increasing with the introduction of smart key vehicles. Results show that drivers can inadvertently leave the engine running in either rotary or smart key vehicles. Results also show that the rate of CO poisoning deaths from vehicle exhaust in enclosed areas is 2 times higher for drivers age 60+ than for all ages.