The present study is based on clinical and roentgenological observation of 35 cases of odontoma that were encountered in past 4 years at Okayama University Dental School affiliated Hospital. The occurrence rate of the odontomas was 0.4% by roentgenographical evaluation of 8980 patients. They included 16 males and 19 females. The youngest patient was 7 years old and the oldest patient was 55 years old. The majority, 28 (80%), were compound odontomas and 7 (20%) were complex odontomas. Most of the compound odontomas had no inflammatory symptoms but the complex odontomas had caused inflammatory symptoms more frequently. The most common pathological sequel was impaction of neighbouring teeth with the prevalence of 74.3%. The most common location of the compound odontomas was in the upper anterior region and the complex odontomas occurred most frequently in the lower molar regions. The diameter of the size of the odontomas was usually between φ 11mm-15mm. The biggest was φ 70mm, and the smallest was φ 4mm.