The ectopic nail is an additional nail located in an abnormal site. It falls within onychoheterotopia that is a rare condition whose pathogenesis is indeterminate. Ectopic nails are distinguished from the double little toenail by aetiology, location and development. The present article illustrates the clinical-morphological and dermoscopic points of view, the diagnostic criteria, the possible pathogenesis and surgical treatment of paediatric onychoheterotopia.