ABSTRACT: Metritis was elicited by intrauterine infusion of tuberculin or killed Campylobacter fetus ssp. venerealis into vaccinated guinea pigs and lipopolysac-charide or immune complexes into normal animals. The local inflammatory response to intrauterine infusion of antigens, lipopolysaccharide, and immune complexes was determined by changes in differential cell counts in the uterine lavage fluid and by histopathological examination of uterine tissue. The percentage of neutrophils was significantly (p < 0.01) greater in uterine lavage fluid collected at 4 hr after infusion of tuberculin into animals vaccinated locally (intrauterine) with M. tuberculosis than in animals vaccinated parenterally (subcutaneously). In contrast, the local response to infusion with C. fetus ssp. venerealis was approximately the same in animals vaccinated intrauterine and subcutaneously with Campylobacter. The systemic response, measured by the delayed type hypersensitivity cutaneous reaction to intradermal injection of tuberculin, was significantly (p < 0.01) greater in animals vaccinated subcutaneously than intrauterine. Similarly, the concentration of Campylobacter antibody in the serum of animals vaccinated subcutaneously was significantly (p < 0.01) greater than in guinea pigs vaccinated intrauterine. The intrauterine infusion of immune complexes, composed of C. fetus ssp. venerealis and corresponding antibody, into the uterus of normal guinea pigs stimulated neutrophil migration into the uterine lumen. Infusion of lipopolysaccharide also stimulated neutrophil migration into the uterine lumen. A correlation between an increased percentage of neutrophils in uterine lavage fluid and infiltration of the uterine epithelium with neutrophils was observed.