Purpose: To compare the effects of retroperitoneal laparoscopic surgery (RPL) and transperitoneal laparoscopic surgery (TPL) on the hemodynamic and ventilatory functions in old patients. Methods: Thirty-two senior patients underwent either RPL or TPL. Swan-Ganz and radial artery catheters were placed to monitor hemodynamic functions. Artery blood samples were obtained to analyze ventilatory functions. Results: For hemodynamic changes in both TPL and RPL, central venous pressure, mean pulmonary arterial pressure and pulmonary capillary wedge pressure significantly increased 10 min after CO2 insufflation and decreased to preanesthesia levels roughly 30 min after insufflation relief. For ventilatory functions, in both TPL and RPL, peak airway pressure, partial pressure of arterial carbon dioxide (PaCO2), end-tidal carbon dioxide tension (PetCO2), carbon dioxide output (VCO2), and the difference between PaCO2 and PetCO2 (Pa-PetCO2) all increased significantly 10 min after CO2 insufflation and returned to the preanesthesia level 20 min after CO2 desufflation. However, increments of PaCO2, VCO2 and Pa-PetCO2 were significantly higher in RPL than in TPL, and did not return to the preanesthesia level until 30 min after CO2 desufflation. Conclusion: For senior patients, TPL and RPL have similar effects on hemodynamic functions. However, RPL tends to cause much more change in the respiratory measurements.