Background Low flow anesthesia (LFA) provides a saving up to 75% and improves the dynamics of inhaled anesthesia gas, increases mucociliary clearance, maintains body temperature, and reduces water loss. LFA has been recommended for anesthesiologists in recent years to avoid high fresh gas flow (FGF). However, LFA use is limited due to associated risks. The main purpose of this study was to investigate whether LFA according to body weight, which is the main determinant of oxygen requirement, is feasible and safe in the normoxia range. The second aim was to show that this method can provide economic benefit. Methods Eighty donor hepatectomy cases were included to study in two groups as prospective, observational. A surgery room and a team were allocated only for this study. Considering the oxygen requirement (approximately 3-3.5 mL/kg/min), for the first 40 cases, 10 mL/kg (group 10) FGF was applied; for the second 40 cases, 20 mL/kg (group 20) was applied. Desflurane (Suprane (c)) was used as an inhalation agent, and analgesia was achieved with remifentanil infusion. Patients' demographic, respiratory, hemodynamic, and tissue perfusion parameters (SpO(2) and NIRS), and comsumption data (anesthetic agent and CO2 absorbent) were collected and compared. Results No significant differences were detected between the groups in terms of demographic data, duration of surgery, and hemodynamic, respiratory, and tissue perfusion parameters. These parameters were within normal limits in all patients at all times. The maximum O-2 concentration in the FGF that maintained FiO(2):0.4 and provided adequate oxygenation during the LFA was 61% (min 56%; max 67%) in group 10, and 47% (min 43%; max 51%) in group 20. The hourly anesthetic agent consumption was significantly different in group 10 than in group 20 (12.4 +/- 4 mL vs. 21.5 +/- 8 mL/h, respectively (p < 0.001). Conclusions We performed 10 mL/kg FGF speed without deviating from the safety limits to be FiO(2):0.4 in donor hepatectomies, reducing the total costs 38% compared with 20 mL/kg FGF.