We studied 308 female and 92 male textile workers employed in a factory that produced synthetic fiber hosiery. The mean age of the women was 38 years, their mean duration of employment 16 years. The mean age of the men was 39 years with a mean duration of employment of 16 years. A control group of 160 female and 78 male nonexposed workers was also studied. Chronic and acute work related symptoms were recorded for all workers. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves from which the forced vital capacity (FVC), the 1-sec forced expiratory volume (FEV 1 ) and maximum expiratory flow rates at 50% and the last 25% (FEF 50 , FEF 75 ) were read. There was a higher prevalence of all chronic respiratory symptoms in exposed than in control workers, although the differences were statistically significant only for dyspnea, sinusitis, and nasal catarrh (P ฯฝ 0.01) in female synthetic textile workers, and for nasal catarrh (P ฯฝ 0.01) in male synthetic textile workers. Occupational asthma was recorded in 3 (0.9%) of the women textile workers, and in 1 (1.1%) of male textile workers. There was a high prevalence of acute symptoms during the work shift, which was greatest for cough (female: 46%; male: 59%), dryness of the throat (female: 49%; male: 40%), dryness of the nose (female: 53%; male: 43%) and eye irritation (female: 46%; male: 36%). Ventilatory capacity data among the synthetic textile workers demonstrated significantly decreased FEF 75 compared to predicted (P ฯฝ 0.05). Our data suggest that inhalation of dust in synthetic textile plants causes the respiratory impairment.