We report the case of an immunocompetent 65-year-old man affected by cutaneous squamous cell carcinoma (cSCC) with lung and biatrial metastatic localisation. In May 2018, the patient underwent lower limb amputation due to the finding of a large ulceration which upon biopsy was found to be a poorly differentiated squamous cell carcinoma (SCC), ulcerated, full-thickness infiltrating from the skin to the underlying bone tissue. After 1 month, a radiological restaging found multiple pulmonary localisations and a right-atrial metastatic localisation. The patient was then studied in-depth and a transesophageal echocardiogram found that the patient had two 2 and 5 cm metastatic localisations in the left atrium and a 3-cm metastatic localisation in the right atrium. Informed about the clinical situation and about the risks of a chemotherapeutic treatment, the patient decided not to start any treatment. This case represents, to our knowledge, the only case of a biatrial metastatic localisation from cSCC and is representative of how cardiac symptoms and signs in patients affected by this disease must be evaluated.