Neuroendocrine carcinoma (NEC) is uncommon in the head and neck and rare in the salivary glands. In the latter location, it may manifest as pain or a palpable mass. These tumors can be quite aggressive, with a tendency toward recurrence and regional and distant metastasis. Because of the limited number of reported cases in the literature, no reliable treatment has been established. We describe the case of a 79-year-old man who presented with a persistent submandibular mass that was suspicious for a malignancy on imaging. Following surgical resection and histopathologic analysis, a diagnosis of poorly differentiated small-cell NEC was made. The patient was further treated with postoperative chemotherapy, and he exhibited no evidence of recurrence or metastasis on follow-up.