Thirty-four beekeepers were interviewed and their blood assayed for the presence of antibodies reacting with bee venom, bee venom phospholipase A (PLA), and whole bee body extract. Following a bee sting, most beekeepers experienced only minimal local tissue reaction. Their serum contained high levels of total antibodies (primarily IgG) reacting to bee venom and phospholipase A. These antibody titres correlated with the frequency of bee stings. Bee venom and PLA specific IgE antibodies were present in serum of some beekeepers. Beekeepers who had experienced allergic reactions were characterized by low total antibody and high venom specific IgE antibody titres. Bee body IgE antibodies were found in varying degree and did not correlate with levels of venom IgE antibodies. There was no difference in the titres of bee body IgE in the sera of beekeepers with and without systemic reactions. The data suggest that allergic reactions are mediated by venom specific IgE and immunity is at least in part a function of other antibodies, probably primarily IgG.