Retronychia is a newly described condition characterized by the embedding of the nail plate into the proximal nail fold. It mainly affects the great toe unilaterally as a result of mechanical factors. It is rarely reported, and its pathogenesis is not fully understood. Nail plate avulsion represents both a diagnostic and a therapeutic approach. We describe a 34-year-old woman with a medical history of congenital malalignment of the toenails, diagnosed as having retronychia, and emphasize the disease pathogenesis and surgical procedure.