Serum levels of Candida-specific IgG(4) antibodies were examined in 66 patients with bronchial asthma, relating to patient age and asthma severity. 1. The levels of Candida-specific IgG(4) antibodies were the highest in patients with 60+years of age, compared to the levels in cases with 0-39 and 40-59 years of age. 2. In cases with 40-59 years of age, the levels of Candida-specific IgG(4) were significantly higher in cases with long-term steroid therapy (severe intractable asthma) than in cases without steroid regimen. The results suggest that increased levels of Candida-specific IgG(4) were observed in relation to patient age and asthma severity.