Metastatic tumors of the gingiva are very rare tumors that are easily overlooked due to the lack of specific signs and symptoms, and pose a challenge to clinicians. Their common primary sites include the lungs, liver, stomach, and kidneys, and they usually occur in the advanced stages of the tumor, and the interval between presentation and death is usually short; therefore, patients with gingival lesions, especially those with a history of malignancy, need to be carefully and accurately diagnosed. Some tumors tend to have insignificant symptoms in the primary focus and secondary gingival swelling as their first symptom. It is often difficult for the pathologist to determine the primary focus, and tests such as immunohistochemistry can assist in the diagnosis. Early and accurate diagnosis and multidisciplinary treatment are conducive to improving the prognosis of patients.