A case in which a growing cystic mass developed in the submandibular area, 6 months following fat injection to the cheek and mandibular area, is described. Histological examination revealed a liponecrotic pseudocyst. It is suggested that subcutaneous masses appearing in an area, which was previously injected with fat, should be excised. Diagnostic aspiration procedures may cause leakage of its oily content and possible further granulomatotic reactions and cysts.