The occupational exposure of workers in 44 commercial dry cleaning facilities to perchloroethylene (127184) was investigated. Concentrations of the chemical in worker breathing zones were measured. Time weighted average exposures were determined for machine operators, pressers, and seamstresses for shift time spent cleaning textiles. Peak samples were also taken for machine operators. The dry cleaning process, work practices, and engineering controls were observed. Owners and operators of the facilities were questioned about changes in the operations affecting worker exposures. Where a combination washer/dryer was used, mean concentrations ranged from 2.5 parts per million (ppm) at the counter area to 21ppm at the 5 minute peak for the machine operator. With separate washer and dryer, concentrations ranged from 2.8ppm for the seamstress to a 5 minute peak of 52ppm for the machine operator during transfer of clothes from one machine to the other. Pressers, seamstresses, and front counter personnel were exposed to significantly lower concentrations than machine operators who spent most of their time near processing machinery. In 5 percent of facilities surveyed, machine operator exposure was above the OSHA 8 hour time weighted average standard of 100ppm, and seven facilities had peak exposures in excess of that allowed. Owners and managers reported that equipment, processing techniques, and work practices had changed little in the past 20 years. The authors conclude that exposure to perchloroethylene among dry cleaning machine operators should be reduced to levels as low as reasonably achievable. Recommendations are made for work practices, including use of a combination washer/dryer unit, ventilation, maintenance, facility layout, and personal protective equipment.