Although gene therapy has been used for correction of metabolic defects in diseases such as cystic fibrosis, as adjuvant treatment in cancer, and in the treatment of infectious diseases, there has been no report of gene transfer to the intact female reproductive tract. We assessed the ability to transfect the human uterus ex vivo and thereby evaluate the applicability of gene therapy to gynecology. The uterine lumen was accessed transcervically, using an intrauterine insemination catheter. pcDNA3.1 plasmid containing the Escherichia coli lacZ reporter gene was delivered to each uterus via liposome-mediated transfection. Control uteri were transfected with empty pcDNA3.1. Immunohistochemical analysis revealed beta-galactosidase expression in the lacZ-treated uteri in endometrial epithelial cells, endometrial stromal cells, and myometrium to a depth of 1.75 cm from the endometrial-myometrial junction. Highest expression was seen in endometrial glandular epithelial cells, with significant expression in the stroma and adjacent myometrium. Each of these cell types in the control uteri showed no beta-galactosidase expression. Successful gene transfection and expression in the intact human uterus can be accomplished easily, rapidly, and efficiently. Gene therapy may have wide applicability in the treatment and study of gynecologic disease.