Organ cultures of human fallopian tube were used to assess the potential role of gonococcal IgA1 protease in infection of mucosal tissue. A genetically cloned IgA1 protease deficient mutant and its wild type parent were used to infect fallopian tube organ cultures. The comparative rate and extent of attachment, invasion and damage to the organ cultures by the gonococcal mutant and its parent type were assessed by scanning and transmission electron microscopy and determined to be indistinguishable from one another. These results indicate that the lack of IgA1 protease does not compromise the gonococcus in its ability to infect previously uninfected human fallopian tube mucosa.