The objective of this study was to examine the effects of TCE on spermatogenesis among a group of workers with varying degrees of exposure to TCE in an electronics factory. A total of 124 workers participated in the study for which 85 were included in the study based on the selection criteria. Semen analysis included volume, sperm density, sperm viability, motility, and morphology. Each worker also had urine collected and analyzed for trichloroacetic acid (TCA) on the day (end of work week) the semen was given. Personal monitoring for environmental TCE exposure was conducted for 12 workers. The mean environmental TCE level was 29.6 ppm (range 9 to 131) and the mean urine TCA was 22.4 mg/g creatinine (range 0.8 to 136.4). The majority of the workers had normal sperm volume (71.8%), density (88.2%), and motility (64.7%). However, the subjects had a low percentage of normal sperm morphology. There were no significant differences in the mean sperm parameters among the "high exposure" (urine TCA > or = 25 mg/g creatinine) and "low exposure" (urine TCA < 25 mg/g creatinine) groups except for sperm density. Prevalence rate ratios of hyperzoospermia were higher with increasing urine TCA levels compared to the "low exposure" group (even after adjusting for marital status of the subjects), suggesting a dose-response relationship.