Salivary duct carcinoma (SDC) is a rare primary salivary gland malignancy characterized by histological features similar to those of ductal carcinomas of the breast. It is regarded as a high-grade malignancy associated with frequent local recurrences and early distant metastases that require aggressive treatment. The typical fine needle aspiration cytology (FNAC) findings in SDC include cellular smears showing tumor cells with eccentric pleomorphic nuclei and a granular cytoplasm arranged in flat sheets or cribriform patterns against a necrotic background. However, the presence of mucin-containing cells in SDC has been rarely described. We report the FNAC findings in a patient with histologically confirmed SDC that demonstrated numerous mucin-containing cells and was subsequently misdiagnosed as a high-grade mucoepidermoid carcinoma. Here we discuss the problems involved in distinguishing SDC from high-grade mucoepidermoid carcinoma on the basis of cytologic findings alone.