Respiratory function and immunological reactions in Croatian sisal textile workers were investigated. The first study was in 1972, and included 50 women (90% of the mill workers). A group of 32 unexposed female office workers served as comparisons. Of the sisal workers, 20 were available for a followup study in 1991, and 30 female office workers served as controls. Respiratory symptoms recorded were chronic cough or phlegm, chronic bronchitis, dyspnea, occupational asthma, and byssinosis. Ventilatory capacity measurements were taken, and skin prick tests were performed against various allergens. Airborne dust was sampled. Results showed that there were no significant differences in chronic respiratory symptoms between the two groups, except for chest tightness (sisal 24.0%, control 0%). Two sisal subjects had typical symptoms of occupational asthma. The followup study revealed significantly higher prevalences of chronic cough, dyspnea, chest tightness, and nasal catarrh. No typical case of byssinosis was available for followup. Of acute symptoms in these subjects, highest prevalences were of chest tightness, cough, and eye irritation (60.0%), followed by dry throat and irritation (45%), dyspnea (35%), bleeding, nasal secretion, and headache (20%). Higher prevalences of all the symptoms were recorded from the sisal workers as against the comparisons. Ventilatory capacity showed statistically significant across shift reductions for forced vital capacity and 1 second forced expiratory volume on Monday and the following Thursday. Immunological tests showed positive skin reactions to sisal extract in 10% versus 5.7% in controls. Increased immunoglobulin-E levels were recorded in two sisal workers. Reactions to house dust were recorded, but sisal workers were negative to jute extract, molds, or cotton. Dust concentrations were 1.918mg/m3 and 1.890mg/m3 in initial and followup studies, both levels being considerably below those recorded in other types of textile mills in Croatia. The authors conclude that there is an excess of respiratory symptoms and lung function abnormalities at the mill, and that symptom severity increases with length of exposure.