Bilateral decentralization of the superior cervical ganglia protects against pulmonary inflammation when measured 8 hr after induction of anaphylaxis in rats sensitized to the nematode, Nippostrongylus brasiliensis. Since anaphylactic shock produces immediate perturbations to the cardiovascular and respiratory systems, we examined whether bilateral decentralization of the superior cervical ganglia modified the responses of these two systems during the first 4 hr of the anaphylactic response. With the exception of the bronchioles, decentralization did not protect against anaphylaxis-associated increases in extravasation of albumin, and the small changes in respiratory function induced by anaphylaxis were unaffected by the denervation. Decentralization did not alter anaphylaxis-induced reductions in blood flow to the gastrointestinal tract; however, blood flow to the kidneys and spleen of decentralized rats was restored more rapidly to normal values. These results suggest that the protective effect of decentralization on the late phase pulmonary inflammation of anaphylaxis is unrelated to early changes in respiratory mechanics, although the protection may be facilitated by the more rapid re-establishment of normal cardiovascular homeostasis.