Dimetridazole and ipronidazole, two veterinary drugs used to treat turkeys, oxidize in vivo to form alcohol metabolites. The parent drugs as well as their metabolites are usually quantitated by high-performance liquid chromatography (HPLC) with ultraviolet detection. The confirmation of identity procedure reported herein uses HPLC for separation followed by thermospray tandem mass spectrometry (MS/MS) of both the parent and the alcohol metabolites. The extraction and cleanup procedures of the regulatory method were used to isolate the nitroimidazoles from turkey muscle tissue fortified at 2 and 10 ppb. An HPLC thermospray MS/MS technique, operating in the daughter ion mode, was used to confirm the identity of dimetridazole, the alcohol metabolite of dimetridazole, ipronidazole, and its alcohol metabolite. Unfortified control tissues were also analyzed and showed no interference.