Effects of glucocorticoid (GC) compounds on inhibitory activity of neutrophils to mycelial growth of Candida albicans were examined by in vitro crystal violet staining method with 14 hr coculture. Both GC hormones (hydrocortisone > or = 6 x 10(-7) M and corticosterone > or = 10(-6)M) and anti-inflammatory GC agents (prednisolone > or = 10(-7) M and dexamethasone > or = 10(-8) M) significantly suppressed anti-Candida activity of murine casein-induced neutrophils. Anti-Candida activity of human neutrophils prepared from peripheral blood was also suppressed by hydrocortisone (> or = 6 x 10(-7) M). These GC compounds did not affect the Candida growth in the absence of neutrophils. Steroidal compounds without anti-inflammatory activity, cholesterol, cholic acid, aldosterone did not suppress neutrophil activity. These results suggest that GCs at their physiological or clinical concentration may suppress anti-Candida activity of neutrophils in vivo.