The physiological response to textile dust exposure has been studied during the working week in a group of spinning operatives with work-related respiratory symptoms and a group of asymptomatic control operatives. Across shift variations in spirometry and bronchial reactivity on Day 1 and Day 4 of the working week have been compared in a case-control study. In addition across week variations have also been studied. Despite well-matched groups, the symptomatics had lower baseline spirometry and higher baseline bronchial reactivity. Very little difference between the two groups was noted for across shift variations, however the symptomatics demonstrated significantly larger across week falls in spirometry than the asymptomatics. The differences between the two groups may be due to factors other than textile dust and cigarette exposure.