A rare case of untreated tongue carcinoma survived for 15 years is presented. A 43-year-old Japanese woman was referred to our department with a 1.8 cm x 1.0 cm white and red non-indurated lesion of the left border of the tongue. The histological examination showed a diagnosis of well-differentiated squamous cell carcinoma. We informed the patient and her family that she had a Stage I tongue carcinoma and needed to receive treatment immediately. However, they refused treatment. Fifteen years later, the patient presented again, complaining of a 55 mm x 40 mm painful gradual-growth swelling of the same site as before, and the clinical stage was T3N2aM0 (Stage IV). The patient agreed to receive radical surgery following preoperative chemoradiotherapy this time. Currently the patient has been free of recurrence for 4 years. Clinical and immunohistochemical features of this rare case are presented and discussed.