Achondroplasia is characterized by undergrowth of long bones and cartilages and by low height. The name of this disease had been called classical chondrodystrophy, dyschondroplasia, chondrodystrophy and micromelia before Parrot reported the term of this disease as Achondroplasia. We are reporting in this paper on an 3-year and 4-month-old boy with achondroplasia. The dental findings are as follows: 1. Open bite and relatively mandibular prognathism were observed in the front teeth. 2. The size, number, shape, structure of the teeth were usual and the tongue was a little bigger than the normal. 3. The metacarpal bones were short and broadening. Mesial, distal border of the prox. phalanges were irregular and also trabecular pattern was abnormal in the hand-wrist P-A view. 4. According to lat. cephalometric analysis, the cranial basis was underdeveloped.