Rats undergoing ocular anaphylaxis induced by systemic or local injection of antigen, topical application of antigen, or topical application of compound 48/80 were evaluated conjunctival goblet cell changes that might be related to anaphylaxis. The number of goblet cells in 1 micron, alkaline Giemsa-stained sections averaged 500/mm2 of epithelium in normal rats; this number was not significantly changed in any of the experimental groups. Goblet cells in control rats occasionally demonstrated evacuation of their contents (less than 1%) or upward displacement of the intracellular bolus of mucus (about 1%); these percentages were not increased in anaphylaxis. Topical application of 2.0 micrograms of histamine induced an intracellular displacement of mucus in both control animals and animals undergoing anaphylaxis. These findings suggest that in ocular anaphylaxis the amount of histamine released may be insufficient to produce such intracellular changes. Our results indicate that in ocular anaphylaxis in the rat, there is no light microscopic evidence of increased mucus discharge from conjunctival goblet cells. Increased mucus in secretions of patients with ocular allergic syndromes may not be attributable to anaphylactic mechanisms alone.