In an epidemiological study carried out in three textile mills at Ahmedabad, India, 929 workers were examined from the spinning departments. The mean prevalence of byssinosis in the blow section was 29.62%, whereas in the card section it was 37.83%. The concentrations of cotton dust (dust less fly) were high in the blow and card sections (4.00 mg/m3 in the blow and 3.06 mg/m3 in the card section). This study suggests that the prevalence of byssinosis is not low in the textile mills of India as reported in many earlier Indian studies.