Carpal tunnel syndrome (CTS) is a common form of hand mononeuropathy that is typi-cally caused by median nerve compression. Although it is often idiopathic, CTS can also result from various conditions, including space-occupying lesions. Tumoral calcinosis, a rare condition characterized by periarticular deposition of calcified masses, is an un-common cause of secondary CTS. We present a case of a 78-year-old woman with idio-pathic tumoral calcinosis that caused secondary CTS. Despite conservative treatments, her symptoms persisted, and diagnostic imaging, including radiographs, computed to-mography, and magnetic resonance imaging, revealed a calcified mass in the carpal tun-nel. A surgical intervention involving carpal tunnel release and excisional biopsy con-firmed the diagnosis of tumoral calcinosis. Postoperatively, the patient showed complete resolution of symptoms, with no recurrence on follow-up radiographs. This case high-lights the importance of considering space-occupying lesions, such as tumoral calcinosis, as a rare but treatable cause of secondary CTS.