We report a case of a large calculus in buccal soft tissue. The patient was a 71-year-old woman. She was referred to our hospital by a dental clinic becaese of a hard mass in the right buccal mucosa. On the basis of the computed tomographic, magnetic resonance imaging, and sialographic findings, an ectopic calculus in the buccal mucosa was diagnosed. Extirpation of the calculus and its capsule was performed through an intraoral approach with the patient under general anesthesia. Histopathological examination revealed that the calculus was similar to the phlebolith. There has been no evidence of recurrence after the operation.