Lipoma is a neoplastic process of well-differentiated adipocytes that is clearly demarcated from the adjacent tissues. An infiltrative lipoma has histopathological features similar to a simple lipoma, with well-differentiated adipose cells. The distinctive difference with infiltrative lipoma is the capacity to infiltrate into surrounding tissues such as muscle fibres, vessels, nerves and bones. Considering the cytologically benign characteristics of this tumour, the diagnosis of infiltrative lipoma must be confirmed by histological assessment to identify margin and involvement of surrounding tissue. This case report provides an additional differential diagnosis (infiltrative lipoma) to consider when seeing a canine patient with facial mass. In the case described here, wide resection of the mandibular infiltrative lipoma provided long-term remission without the need of additional treatment.