The sequence and chronology of deciduous tooth eruption and exfoliation in the rabbit was studied roentgenographically. In the mandible, two molars are erupted at 25 days gestation age. Root resorption of these teeth is apparent by the 7th postnatal day and both have been exfoliated by the 30th day. Development is more variable in the maxillary arch. Two molars and the second incisor tooth are erupted at 25 days gestation age and a third, more anteriorly placed, molar erupts by the 7th postnatal day. All of the maxillary teeth have been exfoliated by the 35th day. Transitory predecessors of the large permanent anterior incisor teeth in both jaws, reported in the literature, were not seen radiographically in our series. The deciduous dental formula, including the first incisors, may be stated: I( ab a ) C( o o ) M( def ef ) , with d the late erupting maxillary molar. The dentition of the rabbit differs from that of other commonly used laboratory animals in two important respects: (a) the deciduous dentition persists for about 1 month postnatally before being completely exfoliated; and (b) all of the permanent teeth are of the continuously erupting variety.