A rare case is presented of a 57-year-old Japanese male with synchronous and metachronous multicentric squamous cell carcinomas (SCC) in the upper aerodigestive tract. During a 9-year-period from the appearance of first primary SCC to autopsy, 14 foci of primary SCC and one severe dysplasia developed in succession in the thoracic esophagus, oral floor, soft palate, uvula, lingual radix, piriform recess, hypopharynx, cervical esophagus, trachea and lingual body. The patient died of severe bronchopneumonia due to Gram-negative bacterial infection that developed as a result of recurrent nerve paralysis. Human papilloma virus and Epstein-Barr virus, which are risk factors, were not detected by immunohistochemistry or by the polymerase chain reaction method. Genetic analysis revealed the absence of point mutations in K-ras codon 12. Heavy consumption of alcohol and excessive smoking may have been responsible for the multicentric carcinogenesis. This is the first case report in the literature of the development of so many primary SCC lesions in the upper aerodigestive tract during such a short period.