The nails are important elements of the finger, not only aesthetically, but also for its functionality. Not only to protecting the tip of the finger helps us but also to perform meticulously fine dexterity activities. Due to the high incidence of nail injuries seen in a trauma emergency service, it is essential to know, at least, basic aspects of the anatomy and physiology of the nail and what should be the appropriate treatment based on the injury presented by the patient. Injuries such as subungual hematomas are resolved in short time, however, more complex lesions require minor surgical intervention to obtain good results. In this chapter, additionally to reviewing the anatomy-physiological aspects of the nail, the principles of treatment of nail traumas are detailed.