To introduce a technique for robot-assisted laparoscopic myomectomy for FIGO type II sub-mucosal leiomyoma with >50% myometrial extension, without endometrial injury. A narrated video demonstration of our technique has been provided. Our patient was a 35-year-old, gravida 1, para 0 woman with secondary infertility. She had been married for three years. She complained of heavy menstrual bleeding and severe dysmenorrhea with a pain score of 10 on visual analogue scale (VAS). Surgery was done after thorough counseling and an informed consent was obtained. Institutional Review Board number: KC17OESI0375, approval date: 21.09.2018. Several steps can be taken to help prevent endometrial injury, and these include: (1) proper preoperative imaging to plan surgery; (2) use of intraoperative ultrasound to determine best location of incision; (3) use of a “cold cut” technique with monopolar curved scissors without energy to avoid obscuring the border between the leiomyoma and the endometrium; (4) careful millimeter by millimeter dissection; (5) use of diluted indigo carmine to aid delineation of the endometrial cavity during dissection. The patient had a normal post-operative course. On follow-up her VAS pain score was 0. Transvaginal ultrasound repeated four months postoperatively showed normalization of uterine anatomy and endometrial contour. Robot-assisted laparoscopic myomectomy may be an option to preserve fertility and minimize endometrial injury. This surgical method allows complete removal of large sub-mucosal leiomyomas in one session with exact suturing.