The pathomorphological picture of experimental infection caused by the infective agent of cholera was shown to have some specific features observed in infections caused by vibrios belonging to the serogroups under study. Infection caused by V. cholerae of serogroup O139 induced some morphological changes in the gastrointestinal tract which were quite characteristic of this disease, but inflammatory changes with the prevalence of proliferative infiltrative processes came to the foreground simultaneously with less developed processes of edema and dystrophic lesions of enterocytes. These specific morphological features in animals infected with V. cholerae of serogroup O139 appeared to be probably due to the production of new surface structures by these strains.