A group of 150 people occupationally exposed to dust from herbs were examined. As a reference group, 50 urban dwellers, not exposed to any kind of organic dust were examined. People were subjected to routine physical examination and to lung function examinations with the LUNGTEST 500 spirometer (MES, Kraków, Poland). The spirometric values of the forced expiratory volume in one second (FEV (1)), vital capacity (VC) and FEV(1)/VC were recorded before and after work. Physical chest examination revealed pathological crepitations in 10 people (6.7 %). The mean baseline spirometric values in the study and reference groups did not show significant differences compared to the normal values. In the herb workers exposed to organic dust the post-shift decrease of all analysed spirometric values was noted. The post-shift decrease of some spirometric values (VC, VC % of normal values) was highly significant (p < 0.01). There was evidenced of a significant positive correlation between the age of examined people and decrease of VC and FEV(1) values. In 12 exposed workers the decrease of FEV(1) or FEV(1) % of normal values higher than 15 % was noted. 50 % of these workers cultivated thyme (Thymus vulgaris L.). This may suggest that dust from herbs, especially thyme dust, may cause acute airway obstruction. In the group showing significant decrease of FEV(1)/FEV(1) % of normal values ( > 15 %) the frequency of reported respiratory work-related symptoms (83.3 %) was higher than in the rest of exposed group (61.5 %). In conclusion, occupational exposure to dust from herbs may cause harmful effects on the respiratory system among herb processing workers. This indicates the need for use of prophylactic measures in this professional group, the more so as number of people occupationally exposed to dust from herbs is growing.