The effects of trichloroethylene (79016) (TCE) on behavioral and cognitive performance were investigated. Nine volunteers were exposed for 8 hours per day for 3 days to 0.50, and 110 parts per million (ppm) of TCE; each exposure session was separated by a 4 day nonexposure period. Breath samples were taken at selected postexposure intervals for TCE and metabolite analysis. During the first and last hour of each exposure session, subjects completed complex reaction time, tachistoscopic perception, digit span, finger dexterity, flanagan coordination, and digit inspection tests. Subjective responses to exposure were also determined. The subjects reported various symptoms including headache, dizziness, and eye, nose and throat irritation. TCE exposure significantly affected performance only on the flanagan coordination test. Sources of variability on the other tests included learning effects, time of day, and subject. Results of breath analyses were not evaluated. The authors note these findings do not substantiate the positive results in a previous study of subjects exposed to 110ppm of TCE. They suggest that the discrepancy could be due to statistical methods, control of exposure concentrations, and exposure design.