The vagina links the organs where gynecologic tumors are located to the outside world. A healthy acidic vaginal environment relies on lactobacilli; a dysregulated vaginal flora is associated with the occurrence, unsatisfactory treatment and poor prognosis of gynecologic malignancies. Using microbial markers to screen the difficult-to-detect characteristics of early tumors may play a key role in prolonging the survival of cancer patients. The discovery of microbes within tumor has led to the consideration of the immunological relevance of internal microorganisms to tumors. This article aims to review the relevance of microorganisms within the above two environments to gynecologic malignancies.