Our knowledge of the morphology and pathogenesis of malignant neoplasms of the female genital tract has traditionally depended heavily on their light microscopic characteristics. The introduction of transmission, and most recently, scanning electron microscopy, into the field of gynecologic pathology has resulted in a considerable improvement in the diagnosis of genital cancers that are difficult to classify and has provided valuable information for a better understanding of their subcellular dynamics and pathogenetic development. This paper describes and illustrates the ultrastructural alterations that are considered specific for the most common malignant and potentially malignant neoplasms of the genital system in this context. The value of electron microscopy in the morphologic study of genital cancers warrants its increased use in routine diagnostic pathology, as well as further evaluation of it in basic research in this challenging area of investigation.