We present a patient suffering from salivary duct carcinoma in the mobile portion of the tongue, arising from a minor salivary gland; this condition is extremely rare. The patient was a 64-year-old woman who presented with a nonpainful, hard mass in her tongue. An aspiration smear showed cells with very scant cytoplasm and pale oval nuclei containing small, single nucleoli. Scattered clusters of small cells had darkly stained nuclei. Neither necrosis nor cribriform areas were seen. The smears suggested a salivary gland neoplasm; however, definitive diagnosis of salivary duct carcinoma remained difficult. Partial glossectomy was performed with a wide margin. Macroscopic examination revealed an unencapsulated, submucosal tumour infiltrating underlying muscle. Microscopic examination revealed a salivary duct carcinoma with comedonecrosis and relatively few cribriform and papillary areas. This case suggests that it may not be easy to establish a definitive diagnosis of salivary duct carcinoma from an aspiration smear if the salivary duct carcinoma is composed of comedonecrosis surrounded by solid tissue in a noncribriform pattern.