Most cancer patients experience nausea and vomiting after surgery. Today, many methods of treatment havebeen developed and used for the control of such symptoms. The most important are drug therapy, relaxation,oxygen therapy and gas therapy. In addition, dexamethasone, massage therapy and using a Venturi mask havealso proven effective. Due to the nature of gas consumption which leads to nausea it is recommended that useof N2O in the operating room be avoided or applied in combination with oxygen or other gases with fewercomplications.