BackgroundRenal cell carcinoma is the third most common tumor that metastasizes to the head and neck, after breast and lung carcinomas. Tongue metastasis as an initial presentation of renal cell carcinoma is extremely rare, and very few cases have been reported. The prognosis is poor. We present a rare case of metastatic renal cell carcinoma that initially presented as a tongue lesion.Case presentationWe report the case of a 55-year-old white man who presented with a large exophytic lesion on his tongue. A biopsy was taken, and pathologic examination showed a poorly differentiated carcinoma including a sarcomatoid component. Subtotal glossectomy with neck dissection were planned, but a positron emission tomographic-computed tomography scan showed a left kidney mass. Immunohistochemical evaluation of the tongue lesion was performed, and it was compatible with metastasis from primary renal cell carcinoma. The biopsy of the renal lesion showed a high-grade unclassified renal cell carcinoma. Although our patient underwent systemic therapy, he died of hemorrhagic complications 3 months after the initiation of therapy.ConclusionTongue lesions require a complete assessment to distinguish a metastasis from a primary cancer in order to give the appropriate treatment.