Abstract The aim of this study is to verify that 10 % of N2O in CO2sufficiently reduces pain to permit laparoscopy under local anesthesia. In nine patients undergoing laparoscopy under local anesthesia for tubal sterilization, a mixture of 86 % of CO2, 10 % of N2O, and 4 % ofoxygen(theGas Mixture) was used for the pneumoperitoneum. For CO2, N2O, and for the Gas Mixture, the pain when blowing over the tongue tip and the pH changes of saline and Hartmann’s solution were estimated. In all nine patients, discomfort was minimal and the intervention was well tolerated, similar to 100%N2O. Tongue tip pain (n=15), onVAS scale, was lower with 86% CO2+10% N2O+4 % O2 (2.4±1.4,P=0.005) and much lower with 100 % N2O (0.3±0.6,P