Background: Uterine leiomyomas are smooth muscle tumors and are the most common type of pelvic tumors in women. Uterine myomectomy, the surgical removal of uterine leiomyomas, is one of the most frequently performed procedures in gynecological surgery. From 2022 to 2024, uterine myomectomy accounted for 29.3% of all surgical procedures performed in the Gynecology Department of the Mongolia-Japan Hospital. Although research in this field has been undertaken in our country, there is a marked paucity of evidence regarding the use of vasoconstrictive agents during laparoscopic myomectomy, which underscores the rationale for the present study. Aim: Present study was aimed to A study of effectiveness of vasopressin for the patients undergoing laparoscopic myomectomy. Materials and Methods: The study was conducted after receiving ethical approval from the Research ethics committee of the Mongolian National University of Medical Sciences (No.24-25/06-02, March 24, 2025). The study data was collected from electronic medical records using a five-category card and was performed using a descriptive research design. Between 2022 and 2024, a comparative study was conducted at the Gynecology Department of the Mongolia-Japan Hospital of the Mongolian National University of Medical Sciences. The study compared the effectiveness of two groups undergoing laparoscopic myomectomy for uterine leiomyoma: 74 cases (Group 1) where vasopressin was used, and 20 cases (Group 2) where traditional vasoconstrictor agent were administered. Data was collected quantitative and qualitative data were coded and analysed using SPSS 26.0 version. Difference of proportions between qualitative variables were tested using chi- square test and numerical variables were tested using independent t-test as applicable. Results: The average age of the participants was 40.48±6.01 years. Among these patients 52.1% (n=94) cases had single uterine fibroid nodules, 34% cases had two to three uterine fibroid nodules, and 13.9% cases had multiple uterine fibroid nodules. Of the study participants 6.4% (n=94) were asymptomatic upon hospital admission, while 93.6% had one or more symptoms related to uterine leiomyoma, with two or three symptoms appearing together. When comparing the average intraoperative blood loss during surgery between the two groups, the traditional vasoconstrictor agent group had 291.5±189.8 ml, while the vasopressin group had 160.6±82.5 ml (95% CI: 74.1-187.6, p=0.000). The surgical duration time for the vasopressin group was 112.4±39.2 minutes, and for the traditional vasoconstrictor agent group, it was 138.2±55.6 minutes (95% CI: 4.1-47.4, p=0.02). The rate of conversion from laparoscopic to open myomectomy was 5% (n=1) in the traditional group, while it was 0% (n=0) in the vasopressin group. Blood transfusion rates were 0% (n=0) for the vasopressin group and 10% (n=2) for the traditional vasoconstrictor agent group (p=0.006). Conclusion The local use of a vasopressin injection during laparoscopic myomectomy for uterine leiomyoma resulted in a shorter surgical duration time and less intraoperative blood loss. Furthermore, it is significant for reducing the use of blood products during surgery. In addition, it significantly reduces the common complications of myomectomy, such as bleeding and the conversion of laparoscopic to open surgery.