The term “field cancerization” was coined by Slaughter in1953 when describing multifocal synchronous and metachronous carcinogenesis in the upper aerodigestive system. Patients suffering from head and neck cancer (HNC) have or develop a second esophageal squamous cell cancer (ESCC) or bronchial cancer (BC) in 5–14% of cases. When a second esophageal cancer occurs in a patient with HNC, the prognosis is generally determined by the ESCC, and, unfortunately, it is poor. Screening and surveillance by Lugol chromoesophagoscopy enable early detection and curative treatment of second esophageal neoplasias. Surveillance appears to result in a survival benefit for HNC patients. Vice versa, patients with ESCC or BC have a risk of about 10% for developing HNC. Periodic pharyngolaryngoscopy is recommended for curatively treated ESCC or BC patients. Patients with field cancerization should be surveilled by a multidisciplinary approach.