Invisible environmental contaminants are those contaminants that possess environmental and/or medical invisibility. Recent studies indicate: (1) that these contaminants can and do have traumatic psychological effects on those individuals who have been exposed to them and (2) that there is a remarkable uniformity to these traumatic affects as they have been found in the various invisible exposures that have been studied to date. The common denominators in all of these situations is the invisibility of the involved contaminants. The adverse psychological effects of the invisible contaminants are as follows: (1) experienced uncertainty, (2) adaptational dilemmas, (3) hypervigilance, (4) nonempirical belief systems about the exposure, and (5) traumatic neuroses. This paper will: (1) review the data that documents the occurrence of psychological effects of the invisible environmental contaminants, (2) present an adaptational model that explains the manner in which these psychological trauma develop, and (3) examine the clinical and public policy implications of these findings.