To identify factors affecting blood loss and operation time (OT) during robotic myomectomy (RM), we reviewed a total of 448 patients who underwent RM at Seoul Asan Hospital between 1 January 2019, and 28 February 2021, at Seoul Asan Hospital. To avoid variations in surgical proficiency, only 242 patients managed by two surgeons who each performed >80 RM procedures during the study period were included in this study. All cases of RM were performed with a reduced port technique. We obtained the following data from each patient's medical chart: age, gravidity, parity, body mass index, and history of previous abdominal surgery including cesarean section. We also collected information on the maximal diameter and type of myomas, number and weight of removed myomas, concomitant surgery, total OT from skin incision to closure, estimated blood loss (EBL), and blood transfusion. Data on preoperative use of gonadotropin-releasing hormone agonists (GnRHas) and perioperative use of hemostatic agents (tranexamic acid or vasopressin) were also collected. Data on the length of hospital stay, postoperative fever within 48 h, and any complications related to RM were also obtained. The primary endpoint in this study was the identification of factors affecting EBL and the secondary endpoint was the identification of factors affecting the total OT during multiport RM. Univariate and multivariate analyses were used to identify the factors affecting EBL and OT during multiport RM. The medians of the maximal diameter and weight of the removed myomas were 9.00 (interquartile range [IQR], 7.00 to 10.00) cm and 249.75 (IQR, 142.88 to 401.00) g, respectively. The median number of myomas was two (IQR, one to four), ranging from 1 to 34. Of the cases, 155 had low EBL and 87 had high EBL. Most myomas were of the intramural type (n = 179). The odds of EBL > 320 mL increased by 251% (odds ratio [OR], 2.51; 95% confidence interval [CI], 1.16-5.42) for five to nine myomas and by 647% (OR, 6.47; 95% CI, 1.87-22.33) for ≥10 myomas. The odds of subserosal-type myomas decreased by 67% compared with intramural-type myomas (OR, 0.33; 95% CI, 0.14-0.80). History of abdominal surgery other than cesarean section was positively correlated with EBL. The weight of the removed myomas and a history of previous cesarean section were not correlated with the EBL. : The number of myomas (5-9 and ≥10), maximal myoma diameter, and history of abdominal surgery other than cesarean section affect the EBL in RM.