The effects of alpha- and beta-adrenergic stimulation on guinea pig eosinophil functions were studied. Both enhanced glucose uptake of eosinophils at a concentration of 5 X 10(-5) M after a 24-hour incubation. Decreased eosinophil chemotaxis and dose-dependent inhibition of arylsulfatase release from eosinophils induced by opsonized Candida albicans were observed when eosinophils were incubated with beta-adrenergic agents, but not with alpha-adrenergic agents. On the other hand, alpha stimulation inhibited phagocytosis of opsonized C. albicans by eosinophils and NBT reduction at concentrations of 8 X 10(-5) and 5 X 10(-5) M, respectively, but beta stimulation at the same concentrations did not. This suggests that the regulatory effect of adrenergic agents on phagocytosis in eosinophils is different from that in macrophages and polymorphonuclear leukocytes.