65 cases of sleep apnea syndrome due to undergo uvulo-palato-pharyngoplasty were subjected to pre-operative and then post-operatoire, after 3 months, polysomnographic recording. The authors analysed the results as a function of several criteria of success described in the literature: postoperative apnea index less than 10%, less than 20% and less than 50% of the pre-operative apnea index. They found a success rate approximately 50%. The importance of the apnea index and pre-operative weight were the only factors predicting the results of surgery. However, the spread in individual values did not allow completely reliable criteria to be established.