We describe a unique case of a sublingual-space schwannoma presenting as a painless, 3 x 2-cm enlarging mass in the oral cavity of a 63-year-old man. Computed tomography demonstrated a distinct, well-encapsulated mass in the right side of the floor of the mouth. Findings on fine-needle aspiration cytology were consistent with a pleomorphic adenoma. Transoral excision was performed. Intraoperatively, the mass appeared to involve the nerve to the mylohyoid muscle. Upon removal, the gross tumor measured 4.4 x 3.5 x 2.5 cm. On microscopic examination, the spindle-cell neoplasm was found to be consistent with a schwannoma. Schwannomas of the sublingual space are exceedingly rare. Moreover, to the best of our knowledge, this case represents the first published occurrence of a schwannoma that arose from the mylohyoid nerve.