Goal-directed fluid therapy optimizes cardiac output and flap perfusion during anesthesia. Intraoperative esophageal Doppler (ED) monitoring has been reported as more accurate and reliable, demonstrating improved surgical outcomes compared with central venous pressure and arterial catheter monitoring. A prospective study of patients undergoing free perforator (deep inferior epigastric artery perforator/anterolateral thigh) flap surgery with intraoperative ED monitoring (51 patients) or central venous pressure monitoring (53 patients) was undertaken. Fluid input included crystalloids, colloids, or blood products. Fluid output included urine, blood, or suctioned fluid. Postoperative fluid balance was calculated as fluid input - output. Fluid input between groups was not different. Fluid output was greater in the ED group (P = 0.008). The ED group showed less fluid balance (P = 0.023), less anesthetic time (P = 0.001), less hospital stay (mean 1.9 days; P = 0.147), less monitoring and flap complications (P = 0.062). ED monitoring demonstrated no monitoring complications, provides a favorable postoperative fluid balance, and may reduce flap complications and hospital stay.