In order to understand the health effects of tetrachloroethylene (TCE) on dry cleaning workers, we surveyed personal exposure to TCE and TCE levels in man. Personal TCE exposure levels ranged from 0.6 to 100.8 ppm (time weighted average, TWA) and in winter the values were 1.1-11 times higher than that in summer. TCE levels in expired air ranged from 0.3 to 87 ppm, in blood from 0.01 to 0.73 micrograms/g, and total trichlorinated compounds (TTC) levels in urine ranged from 0.06 to 1.92 mg/dl. Correlation was highly significant between TCE concentration in blood and TTC concentration in urine (r = 0.927, p less than 0.01), and between concentration of personal exposure to TCE and TTC concentration in urine (r = 0.815, p less than 0.01). Following a three day holiday (non-exposure duration, 90 hr) TCE level in blood decreased from 0.05 to 0.006 micrograms/g, in expired air from 1.0 to 0.3 ppm and in TTC level in urine from 0.24 to 0.08 mg/dl respectively.