Metastatic head and neck squamous cell carcinoma (HNSCC) is a rare cause of cardiac tamponade. We report on a 62-year-old male who presented with metastatic squamous cell carcinoma (SCC) that caused cardiac tamponade secondary to a primary SCC originating from the retromolar trigone of the oral cavity. The clinical diagnosis was confirmed by physical examination, echocardiography and complete resolution of symptoms after pericardial fluid drainage. Cytologic examination of the pericardial fluid was the only investigational tool able to render a definitive evidence of malignant pericardial effusion. However, evidence of a hemorrhagic pericardial effusion must raise the suspicion of a malignant etiology regardless of the result of the cytologic examination. Metastatic HNSCC may involve multiple organ systems including the heart. We report this rare clinical presentation of cardiac tamponade as the initial location of distant metastasis. Otolaryngologists should keep a high index of suspicion and pay special attention to the symptoms arising on the non-head and neck sites to establish an early diagnosis and prompt management of the disease process.