Climbers who have suffered a previous episode of high altitude pulmonary edema (HAPE) are at significantly increased risk of developing it again on return to high altitude. In spite of the high mortality associated with HAPE, some climbers are willing to take this risk in order to summit the tallest mountains in the world. This is a case report of a climber who suffered an episode of HAPE partway up Mount Everest. He was determined to complete his summit attempt that same climbing season, which would involve a return to extreme altitude less than 3 weeks following recovery. Based on experimental evidence suggesting that sildenafil, salmeterol, and acetazolamide may have therapeutic value for both the prevention and treatment of HAPE, he used these medications for secondary prevention. He was able to successfully reach the summit of Mount Everest and return to base camp without any evidence of recurrence of pulmonary edema. This provides clinical evidence that medication can be used to increase the safety margin for HAPE-susceptible individuals traveling to extremely high altitudes.