Given the wide range of available health care personnel handwashing agents, selection of an appropriate product may be difficult. This decision may be made on the basis of user preference, cost, or other factors unrelated to product effectiveness. Four criteria—efficacy, safety, cost, and acceptability—are appropriate for systematic evaluation of handwashing products. These criteria are applied to para-chloro-meta-xylenol (PCMX), a compound used with increasing frequency in health care personnel handwashing agents. Published data regarding the biochemical properties, efficacy, and safety of PCMX are summarized. We conclude that the substance appears to be safe and efficacious. However, the activity of PCMX is highly formula-dependent and many of the studies available in scientific literature have been conducted in Europe using a variety of testing conditions and formulations different from those currently available in the US. Clinical studies of marketed formulations are beginning to appear in the literature. Such studies will provide the data needed for adequate product evaluation.