The purpose of this study was to evaluate the prevalence of mesiodens at pediatric dental clinic in Anyang, Kyeong Gi-Do. From retrospective reviews of all patients who visited Kizwell pediatric dental clinic from 2003.4-2006.4, 241 patients (289 mesiodens) who were shown to have mesiodentes were examed by a periapical radiograph and a panoramic radiograph. The incidence of mesiodens was 3.42% and the ratio of male/female (184/57) was 3.2:1. The number of supernumerary teeth was one in 193 cases (80%), two in 48 cases (20%). The mesiodens was placed at left side more frequently and the most common shape was conical type (208, 78%). Of 289 mesiodens, the direction of the crown of the mesiodens was inverted in 156 (54%), in a normal direction in 104 (36%), in a horizontal direction with regard to the tooth axis in 29 (10%). Early diagnosis of the mesiodens allow the most appropriate treatment, often reducing the extent of surgery, orthodontic treatment and possible complications.