The role of preoperative chemotherapy for esophageal cancer still remains controversial. Only one study of the recently published, randomized controlled trials in potentially resectable esophageal cancer has shown improvement in survival by preoperative chemotherapy compared to surgery alone. Nevertheless, there has been a consistent observation that in patients who respond to preoperative therapy survival was significantly prolonged. Therefore, a diagnostic test that allows prediction of response is considered to be crucial for the future use of preoperative chemotherapy in patients with esophageal cancer. Molecular markers for response prediction and reliable non-invasive techniques such as FDG-PET are not yet established. At the moment therefore responder should undergo esophagectomy for definitive curative treatment, whereas non-responder may undergo individualized salvage therapy.