Infantile hemangiomas (IH) are benign vascular tumors consisting of a collection of immature cells, including progenitor stem cells and disorganized blood vessels. They are the most common benign tumors in childhood. Recently, there have been significant, exciting advancements in the understanding of the pathogenesis and treatment of infantile hemangiomas, which are discussed in this review. The decision to initiate treatment for IH is based on many factors, including size and location, functional compromise, psychosocial implications, and risks and benefits of the proposed therapy. For most families of children with hemangiomas, education about the natural history of IH and reassurance are often the only "treatment" required. A minority of patients with large, complex lesions or lesions that cause functional compromise require early intervention. These patients and families benefit from a multidisciplinary approach to care in vascular birthmark centers. Ongoing multi-institutional clinical trials will provide further important data on the efficacy and safety of hemangioma treatments.