This paper describes a case of bilateral Warthin's tumors of the parotid glands associated with amelanotic malignant melanoma of the maxillary gums in a 66-year-old man. The patient twice underwent neck dissection for his malignant melanoma. Although these Warthin's tumors were clinically asymptomatic, histological examination revealed them in the parotid regions of the dissected tissue. Clinical features and incidentally detected cases of Warthin's tumor are discussed.