Nineteen dairy farmers with nasal symptoms associated with working in cowhouses participated in the study. Nasal challenge with bovine epithelial antigen (BEA) and bovine urinary antigen (BUA) was made before and after the indoor feeding season. Nasal challenge made before the indoor feeding season with BEA was positive in five patients and three of them showed positive reaction in nasal challenge also with BUA. After the indoor feeding season the results in nasal challenge with BEA were approximately equal to BEA and four of them showed positive response in nasal challenge to BUA. However, we did not find any significant increase in sensitivity in nasal challenge to BEA or BUA after the indoor feeding season. In addition to these patients, two patients who were excluded from nasal challenge before the indoor feeding season showed positive results in nasal challenge after the indoor feeding season with both BEA and BUA. Our results suggest that BUA in addition to BEA may have significance to nasal symptoms.