Background: The purpose of the study was to compare the safety of local injection of 6 units of pituitrin diluted to 20 mL vs 6 units of pituitrin diluted to 10 mL for laparoscopic uterine fibroid (UF) surgery. Methods: This was a randomized clinical trial of patients scheduled for laparoscopic UF surgery at Fu Xing Hospital, Capital Medical University, Beijing, China. Ninety-six patients were divided into two groups according to the concentration of pituitrin utilized: Group1 (6 units of pituitrin diluted to 20 mL for all injection) 48 cases; Group2 (6 units of pituitrin diluted to 10 mL for all injection) 48 cases. The observation indicators were mean arterial pressure (MAP1) and heart rate (HR1) upon entering the operating room; the lowest mean arterial pressure (MAP2) and the highest heart rate (HR2) within 5 minutes after injecting pituitrin; the highest mean arterial pressure (MAP3) and the lowest heart rate (HR3) within 30 minutes after injecting pituitrin; hemoglobin (Hb1) and hematocrit (Hct1) within one week before surgery; hemoglobin (Hb2) and hematocrit (Hct2) within one day after surgery; and the time for the mean arterial pressure to return to the level of entering the operation room after using pituitrin (Recovery Time). Results: All baseline and observation data showed no statistical difference between the two groups. Conclusions: The safety profile of local injection of pituitrin in the 6 units of pituitrin diluted to 20 mL and 6 units of pituitrin diluted to 10 mL are the same when used for laparoscopic UF surgery.