Specific IgG antibodies against bee venom and bee venom components were studied in the serum of 40 bee-sting patients, 60 bee keepers, and 31 control subjects. The highest titres were observed in successfully hypothesized patients and in bee keepers. Subclass-typing in bee-sting allergic patients showed the highest antibody levels in subclass IgG2, followed by IgG3, IgG 4 and IgG1. During hyposensitization, a rise in specific IgG antibodies in all subclasses and against bee venom and all its components was found. The allergic reaction to bee stings disappeared with the rise of specific IgG antibodies, as demonstrated by a bee-sting challenge. After 6 months of hyposensitization therapy, the specific IgG antibodies remained above, and the specific IgE antibodies fell below, the pretreatment levels.