Basal cell carcinoma (BCC), the most frequent malignant skin tumor observed in Caucasian adults, especially males, occurs mainly in sun-exposed areas of the body. BCC in the periungual tissues, such as proximal nail fold, nail matrix, nail bed and hyponychium, is rarely reported. We report a patient with two synchronous BCC of the periungual tissue localized in the IV and V fingernail, effectively treated with Mohs micrographic surgery.