A 3-year-old boy presented to the clinic with a dark spot in his hair that measured 3 cm by 3 cm (Panels A and B). The skin in this region was lightly pigmented, with dark hairs; the lesion had been more pigmented at birth. There was no pain, pruritus, or bleeding, and the lesion had no notable growth. A congenital nevomelanocytic nevus was diagnosed. Such nevi are often present at birth but can develop later in life. Congenital as compared with noncongenital nevomelanocytic nevi confer a high risk of transformation to melanoma. Although biopsy or excision is often considered for these nevi, neither has been performed in this case, since the pigment is fading and the lesion is small and shrinking. Yearly dermatologic follow-up was recommended, and the patient and his parents were advised to alert the physician should changes appear.