A case of Marfan's syndrome complicated by annulo-aortic ectasia with pectus excavatum (Wada's 3rd grade classification) and aortic regurgitation (Seller's 1st grade) is reported in a 36-year-old man. We performed one-stage operation combining Bentall's procedure for the annulo-aortic ectasia and sternal elevation for the pectus excavatum. Few reports of one-stage operation for pectus excavatum and annulo-aortic ectasia in Marfan's syndrome have been published. If both diseases are present and surgical indications permit, one-stage operation can be performed to ensure protection of the heart and a satisfactory postoperative course. The best approach to the heart to obtain the most favorable operating field and the best chestplasty method that also assures closure of the median sternotomy are important considerations in one-stage operation. The most appropriate combination of these two operational variables must be assessed in each case.