Background The ideal vaginoplasty must be successful functionally as well as have a natural appearance, and also must retain its functionality and appearance over the long term. Conventional vaginoplasty techniques have functional limitations and are associated with recurrent complications, but rectosigmoid vaginoplasty is known to have a high satisfaction rate due to its functional similarity with the vagina. We conducted the present study to assess the usability of rectosigmoid vaginoplasty over the course of long-term follow-up. Methods From March 1992 to February 2014, 84 patients were treated with rectosigmoid vaginoplasty; 44 had gender identity disorder, 29 had vaginal agenesis, 8 had female pseudohermaphroditism, and 3 had gynecologic malignancies after radical pelvic surgery. This retrospective study was based on a review of the patients' records, clinical examinations, complications, and questionnaires about appearance, function, and sexual intercourse. Results All patients who underwent rectosigmoid vaginoplasty were discharged within 2 weeks without surgical flap loss. The early complications were partial flap necrosis, difficulty in defecation, mucous hypersecretion, and postoperative ileus. The late complications were vaginal introitus contracture, vaginal prolapse, and difficulty in urination. The mean length and diameter of the neovagina 3.4 years after rectosigmoid vaginoplasty were 13.2 cm and 3.8 cm, respectively. On questionnaires about satisfaction, 70% of patients reported excellent satisfaction, 11% good, 12% fair, and 7% poor. Conclusions Rectosigmoid vaginoplasty is useful, safe, and well-accepted operative method with good functional and cosmetic results, such as natural lubrication and adequate vaginal length and width obtained without requiring the use of a dilator.