The immunoassay screening of benzodiazepines in urine is one of the most important methods of drug analysis in clinical and forensic laboratories. We experienced an unusual case of poisoning wherein the result of Triage DOA immunoassay screening was negative, although Depas (etizolam) was detected in the blood of the victim who had been suspected to prescribe Depas by gas chromatography-mass spectrometry. Depas has been widely used for the treatment of anxiety in Japan. Three immunoassay screening devices (AccuSign BZO, Monitect-3, and Fastect II) were evaluated for their specificity for etizolam, its 2 major metabolites M-III and M-VI, and other metabolites of benzodiazepines in urine. With AccuSign BZO, etizolam, M-III, and M-VI could be detected at concentrations of 1,000 ng/mL in urine; however, they could not be detected even at concentrations of 25,000 ng/mL with the other kits. In the case of etizolam poisoning, the result of AccuSign BZO was positive; however, Triage DOA, which is mainly used for the detection of drugs in urine at intensive care units (ICUs) or forensic laboratories, showed negative result for benzodiazepines. The concentrations of etizolam and its metabolites in urine were measured by the established high-performance liquid chromatographic method. The concentrations of M-III and M-V were 700 and 1,600 ng/mL, respectively. AccuSign BZO demonstrated higher specificity-than the other screening kits for the detection of etizolam and its metabolites in urine. Therefore, the types of drugs detected would be increased by combining Triage DOA with AccuSign BZO in ICUs or forensic laboratories.