The distribution of lysozyme in the endocervix of estrous, pseudopregnant, and ovariectomized rabbits was studied using two different immunocytochemical techniques—the unlabeled antibody enzyme method of Sternberger et al. (1970) and the peroxidase-labeled antibody method of Taylor and Burns (1974). With both procedures, a fine immunostaining precipitate was seen over the entire area of basal mucous granules, while immunodeposits were coarser and mostly located in the outer zone of central and apical granules. A nonspecific staining was noted when tissues were reacted with peroxidase-antiperoxidase complex alone. This troublesome artifact was abolished by preincubating tissues with human IgA. This step did not affect the specific immunostaining for lysozyme yet nonspecific staining was absent from specificity and method controls carried out for both immunocytochemical procedures. The presence of high levels of lysozyme in the endocervical epithelium of estrous rabbits was also confirmed in enzymatically isolated endocervical epithelia using the lysoplate method of Osserman and Lawlor (1966). Mucous granules and immunostainable intracellular lysozyme were abundant during estrus, decreased during early pseudopregnancy, and were absent after longterm ovariectomy. However, they were restored by the administration of estradiol (5 μ/12 hours/10 days) to ovariectomized animals. These data indicate a common hormonal regulation and secretory mechanism for endocervical mucous glycoproteins and lysozyme.