Birthmarks in newborns can be classified as vascular, melanocytic or pigmented, or markers of underlying developmental abnormalities of the nervous system. A nevus simplex is a benign capillary malformation. Newborns with a nevus flammeus can be safely treated before one year of age with a pulsed dye laser to reduce the visibility of lesions. Infantile hemangiomas should be treated with systemic beta blockers if there is a risk of life-threatening complications, functional impairment, ulceration, underlying abnormalities, permanent scarring, or alteration of anatomic landmarks. Dermal melanocytosis is a benign finding that is easily recognized and does not warrant further evaluation. A solitary congenital melanocytic nevus that is less than 20 cm in diameter may be observed in primary care; children with larger or multiple nevi should be referred to pediatric dermatology due to the risk of melanoma. Newborns with skin markers of occult spinal dysraphism (other than a simple, solitary dimple) should have lumbar spine imaging using ultrasonography or magnetic resonance imaging.