Lipomas are the most frequent mesenchymal neoplasms of the human body, being rare in the oral cavity. In the histopathological aspect, they are constituted basically of mature adipocytes. A 21-year-old man, with no comorbidities or allergies, presented with a nodule in the left mandibular region, with swelling of the chin region to the insertion region of the masseter, intraorally with grooving, ovoid-shaped, fibroelastic consistency, and coloration similar to the adjacent mucosa. Ultrasonography of the region was initially required, showing a solid, circumscribed, echogenic nodule with lobulated margins measuring 3.7 x 2.4 x 4.3 cm, compatible with lipoma, and panoramic radiographic examination showed no changes. An incisional biopsy was performed, the histologic examination revealed fragments of mature adipose tissue surrounded by a thin capsule of connective tissue, confirming the diagnosis of lipoma, so the treatment was surgical excision. The patient was followed up, with no signs of recurrence of the lesion. Lipomas are the most frequent mesenchymal neoplasms of the human body, being rare in the oral cavity. In the histopathological aspect, they are constituted basically of mature adipocytes. A 21-year-old man, with no comorbidities or allergies, presented with a nodule in the left mandibular region, with swelling of the chin region to the insertion region of the masseter, intraorally with grooving, ovoid-shaped, fibroelastic consistency, and coloration similar to the adjacent mucosa. Ultrasonography of the region was initially required, showing a solid, circumscribed, echogenic nodule with lobulated margins measuring 3.7 x 2.4 x 4.3 cm, compatible with lipoma, and panoramic radiographic examination showed no changes. An incisional biopsy was performed, the histologic examination revealed fragments of mature adipose tissue surrounded by a thin capsule of connective tissue, confirming the diagnosis of lipoma, so the treatment was surgical excision. The patient was followed up, with no signs of recurrence of the lesion.