Head-and-neck cancer is frequently associated with esophageal cancer. Because the operative procedures for these synchronous double cancers are too invasive, definitive chemoradiotherapy tends to be applied as an initial treatment. A salvage esophagectomy for either recurrent or residual disease after definitive chemoradiotherapy in patients with such double cancer has never been reported. We reviewed 21 patients with esophageal cancer who underwent a salvage esophagectomy after definitive chemoradiotherapy. Among them, the treatment course of five patients who underwent a salvage esophagectomy for patients with synchronous double cancers of the esophagus and head-and-neck region was analyzed. Because head-and-neck cancer was well controlled after chemoradiotherapy in all five patients, a salvage esophagectomy was indicated for either recurrent or residual esophageal cancer after definitive chemoradiotherapy. Anastomotic leakage developed in four patients; however, no other complications including pulmonary complications were recognized. All of them were discharged to home and three of them are still alive without any recurrence for 20-43 months. A salvage esophagectomy should be considered as a treatment option for either recurrent or residual esophageal cancer with well-controlled head-and-neck cancer after definitive chemoradiotherapy when complete resection of the esophagus is expected.