The object of this study was to assess the relationship between occupational Portland cement dust exposure and respiratory health. Respiratory symptoms and ventilatory function were studied in a group of 591 male Portland cement workers employed in four cement plants. The prevalence of chronic respiratory symptoms was higher in exposed than in control workers. The exposed group had a significantly lower mean forced vital capacity (FVC), forced expiratory volume at 1 s (FEV1), and forced expiratory flows after exhalation of 50% and 75% of the vital capacity (FEF50, FEF75) than the control group. The data suggest that occupational exposure to Portland cement dust may lead to higher prevalence of chronic respiratory symptoms and the reduction of ventilatory capacity.