Solitary median maxillary central incisor syndrome (SMMCIS) is a rare abnormality characterized by the presence of a central incisor positioned at the maxillary mid-axis. This morphologic defect also can be associated with other diseases. The purpose of this paper was to present a case report of a 4-year-old twin child with SMMCIS. The patient showed a symmetrical primary maxillary central incisor located at the midline, with an absence of labial frenulum, an indistinct philtrum, and an incisive papilla. Radiographic examination confirmed the presence of only a maxillary central incisor in both dentitions. The patient was referred for a genetic and otolaryngological assessment, however, no other abnormality than the ones reported were detected.