Situs inversus totalis is a rare congenital condition in which the viscera are transposed as a mirror of normal arrangement. We present a 43-year-old man with nasopharyngeal carcinoma who had right neck mass for 3 months. In addition to hypermetabolic lesions in the nasopharynx and right neck, the FDG-PET scan for initial staging showed transposed heart, liver, spleen and stomach, suggestive of situs inversus totalis. The chest X-ray film and abdominal sonography showed compatible findings.