The ultimate goals of environmental sampling are the protection of health, or barring that, the assessment of health impact to exposed populations. However, environmental samples collected for undefined or poorly defined reasons and that are not part of a feasible strategy of hazard identification, intervention, and follow-up will likely be of limited value. Military commanders and their advisors must be aware of the need to quickly identify potential hazards and to respond appropriately with a comprehensive plan that may include sampling. Before samples are collected, the following must be adequately addressed: (1) the reason for sampling, (2) the parameters to be measured, (3) the possible range of results that might be obtained, and (4) the actions that will be taken in response to various results. Additionally, communication of the risks to commanders and the potentially exposed population is important, particularly if the results are inconclusive.