The melanotic neuroectodermal tumor of infancy is a rare neoplasm arising in the first year of life. A 33-day-old female infant had an enlarged alveolar ridge on the right anterior maxilla. Intraoral examination revealed a nonulcerative swelling at the site. An intraoral radiograph showed an ill-defined radiolucency on the right anterior maxilla and displacement of primary incisors from their alveolar sockets. CT scans revealed an expansion of the surrounding bone and partial destruction of the anterior wall of the premaxilla. Histopathologic examination showed the cytoplasm of neuroblastic cells and eosinophilic, epithelioid cells frequently contained a dark brown granular pigment that stained positively to vimentin and HMB45, focally positive to NSE and cytokeratin. Four weeks after the operation, CT scans showed a rapidly growing soft tissue mass occupying right maxillary sinus encroaching to the orbit and nasal cavity. The final diagnosis was made as a malignant melanotic neuroectodermal tumor of infancy.