Woolly hair nevus consists of a patch of curly and hypopigmented hair that is restricted to an area of the scalp. It is usually benign but it can be associated with other systemic findings. Trichoscopy and dermoscopy may be useful when analyzing this entity. The authors describe a case of woolly hair nevus in a 5-year-old boy and present a review of the literature of woolly hair nevus, including classification, histopathology, associated systemic findings, and the recent described genetic mutations