Retronychia is a process of a nail embedding itself into the proximal nail fold due to an incomplete shedding of the nail, and this usually occurs after physical trauma. Retronychia causes persistent paronychia and defective nail growth on the patients. Simple avulsion of the superimposed nail is curative. A 17-year-old man presented with tender erythema and swelling on the proximal nail fold of the right 3rd and 4th fingers for 2 months after an operation that was performed due to metacarpal bone fracture. The second patient was a 25-year-old male who presented with a 1-month history of persistent paronychia on his right great toe after blunt trauma. For both patients, simple avulsion of the damaged nail was curative and underlying new nails were revealed. We report here on two cases of retronychia that could be easily overlooked and such cases have not been previously reported in the Korean dermatologic literature. (Korean J Dermatol 2010;48(1):39∼42)