Melanotic neuroectodermal tumor of infancy (MNTI) is a rare entity primarily affecting the craniofacial bones during the first year of life, with only 5 reported cases involving peripheral long bones. We herein present a case of MNTI in the tibia of an infant, with a somewhat atypical presentation, and a noteworthy clinical course characterized by progressive spontaneous resolution without therapy, thus sparing the child the trauma of amputation. There is no evidence of active residual or recurrent disease with 13-year follow-up. To the best of our knowledge, essentially all reported cases of MNTI have received empirical treatment, some at the price of mutilating surgery or fatal chemotherapy. We propose that the necessity of aggressive treatment be evaluated on a case-by-case basis, especially in patients with diffuse periosteal involvement, as in this patient. A trial of watchful waiting can be considered when treatment would involve substantial morbidity or risk of complications.