Bowen's disease is the most frequent carcinoma of the nail apparatus. It may develop into frankly invasive squamous cell carcinoma of the nail and the two lesions have therefore coolectively been called epidermoid carcinoma of the nail. Bowen's disease is probably not that rare and many cases escape diagnosis because it may mimick a variety of different diseases. Some cases were linked to HPV 16, 34 and 35, but chronic radiodermatitis may also play an aetiological role.The most frequent clinical appearance is that of a non-healing wart in an elderly person. It may arise in the lateral nail groove, in the nail bed or matrix. Rare clinical manifestations are fibrokeratoma-like appearance, whitish cuticle and pigmented Bowen's disease. Occasionally, a rock-hard keratotic lesion similar to pachyonychia congenita can be observed. Ulceration is commonly considered a sign of development into invasive cancer. Treatment of choice for ungual Bowen's disease is Mobs' micrographic surgery and defect repair according to its extent. We prefer a modified Schernberg nail flap over secondary intention healing and free grafts, but a cross-finger flap may be indicated after removal of the entire nail organ. This usually allows to save a functionally normal and cosmetically acceptable digit to be preserved. Finger or toe tip amputations are not necessary for Bowen's disease of the nail.