Although drug-sniffing dogs have proven reliable in detecting invisible traces of certain important drug components, they obviously cannot specify the types of drug vapors and their strength. In the last few years, the use of ion mobility spectrometry in the detection of traces of controlled substances has improved. In 1997 portable electronic drug detectors are becoming an adjunct to police dogs. Companies such as Barringer, CPAD, and Scintrex in Canada, as well as others in the United States and throughout the world are now producing smaller, lighter, and more efficient equipment. Such equipment is already being used by several law enforcement agencies in the world. In Canada, Canada Customs and Correctional Services own some equipment and are currently using it in an effort to increase their capabilities of detection. In the United States, the drug Enforcement Administration, the FBI, U.S. Customs, and the U.S. Coast Guard, among other law enforcement agencies, use such equipment. Some U.S. agencies have been using their equipment to collect and test samples from homes, warehouses, trailers, trucks, cars, airplanes, clothing, bags, boxes, currency, papers, hands, and hair. Drug-sniffing dogs are useful in conducting a relatively rapid search of an area without having to take multitudes of sample materials from throughout the area. Ion mobility spectrometry can then be used to confirm the dog's findings and determine the characteristics of the sample in the field. A case study of the use of the equipment is provided.