During laparoscopic myomectomy, it is difficult to determine the actual blood loss volume because physiological saline is used for lavaging to detect the bleeding point or to ensure no active bleeding site. We attempted to estimate blood loss by measuring the waste irrigation fluid's hemoglobin (Hb) concentration using HemoCue (HemoCue, Angelholm, Sweden). Twenty-three women enrolled in our study. After the end of laparoscopic myomectomy, the waste irrigation fluid's Hb content was measured using HemoCue. We estimated blood loss using the following formula. Estimated blood loss (ml)= [waste irrigation fluid volume (ml)]x[Hb concentration in waste irrigation fluid (g/l)]/[patient's preoperative Hb level (g/l)]. The demographic data of the patients showed 35.4 years in age, 159.6 cm in height, and 50.7 kg in weight (mean). The total lavage fluid's Hb level ranged between 0.2 approximately 4.7 (g/l). The total blood loss estimation was calculated and ranged between 17.6 approximately 725.2 ml. There was no significant correlation between the calculated blood loss and the difference in Hb level (Hb level on the first postoperative day minus preoperative Hb level). The HemoCue needs only 10 mcl of blood and it takes only about 45 seconds to produce the result. Furthermore, the HemoCue is a reliable device for measurement of blood hemoglobin concentration. Our method is easy and quick to perform, and blood loss estimation and surgeon's experience (subjective method) show accordance.