This study describes an informatics effort to track subjects through a National Pharmaceutical Stockpile (NPS) distribution drill. The drill took place in Seattle on 1/24/2002. Washington and the State Department of Health are among the first in the nation to stage a NPS drill testing the distribution of medications to mock patients, thereby testing the treatment capacity of the plan given a post-anthrax exposure scenario. The goal of the Public Health Informatics Group at the University of Washington (www.phig.washington.edu) was to use informatics approaches to monitor subject numbers and elapsed time. This study compares accuracy of time measurements using a mobile phone Java application to traditional paper recording in a live drill of the NPS. Pearson correlation = 1.0 in 2 of 3 stations. Differences in last station measurements can be explained by delay in recording of the exit time. We discuss development of the application itself and lessons learned. (MeSH Bioterrorism, Informatics, Public Health)