The purpose of the study was to confirm there is a consistent postmortem distribution of zolpidem in postmortem blood and body tissues, and/or fluids making it possible to estimate zolpidem blood concentrations from fluid and tissue concentrations. The samples for the study were zolpidem-positive fatalities located in the CAMI ToxFlo database at the FAA's Bioaeronautical Sciences Research Laboratory. A UPLC/MS method was developed and validated. The LDR, LOD, LOQ, accuracy, precision, and matrix effect were evaluated. The specimens were analyzed for the distribution of zolpidem. The results of this study confirmed there is a consistent postmortem distribution of zolpidem found in the spleen, kidney, and lung; making it possible to roughly estimate, zolpidem blood concentrations from these tissues.