Humans contract a variety of serious diseases through inhalation of infectious aerosols. Thus, the importance of monitoring air for microbial, toxic, or allergic content is recognized in clinical, occupational, and biodefense arenas. However, accurate monitoring of potentially contaminated environments can be hampered by selection of aerosol samplers with inadequate performance for the intended task. In this study, 29 aerosol samplers were evaluated based on their respective air flow, size, weight, power consumption, and efficiency in sampling particles in the respirable range. The resulting data demonstrates that sampling air flow and efficiency vary widely, and cannot be predicted from the physical characteristics of air samplers, and hence, that proper selection of air samplers should be more involved than shopping for a device based on the limited characteristics that are published by the manufacturers. The findings are summarized in an approach to rationally select bioaerosol samplers for use in infection control and environmental biomonitoring. The presented data demonstrates that inadequate selection of air samplers could result in a failure to collect particles of interest and thus, underestimate the risk and provide a false sense of security in contaminated health care settings and environments contaminated with infectious or toxic aerosols.