This study was a part of a collaborative U.S./E.U. international research effort (Roadside Testing Assessment, ROSITA II) to assess illegal drug use among motor vehicle operators suspected of driving while under the influence of drugs and to evaluate the effectiveness of point-of-collection oral fluid drug detection technologies. A goal of the study was to assess commercial oral fluid drug testing devices for potential use in law enforcement. Ten devices were evaluated in the laboratory for their ability to meet manufacturers' claimed (and proposed) cutoff concentrations for the detection of amphetamine(s), cocaine/metabolite, opiates, cannabinoids, and benzodiazepines (2 devices). The field study portion of the research was conducted in major cities in the United States and Western Europe by teams of scientists working in collaboration with the local police. In Salt Lake City, Utah, the Drugwipe, Securetec, Ottobrunn, Germany (Securetec) oral fluids drug testing device was also evaluated in the field by testing suspected drug-impaired drivers. During the initial phase of the field study, 40 subjects were recruited. Drugwipe results were compared with laboratory-based immunoassay and mass spectrometry results and demonstrated that calculated sensitivities were between 75% and 100% depending on drug class. Specificities varied from 36% for cannabinoids to over 95% for opiates. During the second phase of the field study, 267 subjects were recruited. The Drugwipe sensitivities were 36.4%, 35.9%, 42.9%, and 7.7%, respectively, for amphetamine(s), cocaine, opiates, and cannabinoids. The Drugwipe specificities were 99.2%, 97.4%, 99.6%, and 99.6%, respectively, for amphetamine(s), cocaine, opiates, and cannabinoids. Drugwipe failed to meet the study criteria for acceptable device performance, required performance sensitivities, and specificities 90% or greater.