PURPOSE: To examine the relative presentation frequency of children with upper limb congenital anomalies at 3 Midwestern referral centers using the Oberg, Manske, and Tonkin (OMT) classification and to assess the utility of this new classification system. METHODS: 641 individuals with 653 congenital upper extremity anomalies were identified at 3 hospitals in 2 large metropolitan areas during a 1-year interval. Patients were identified prospectively and the specific upper extremity anomaly and any associated syndromes were confirmed using medical records and radiographs. We applied the OMT classification that categorizes anomalies using a dysmorphology outline as malformations, dysplasias, deformations, and syndromes, and assessed its utility and ease of use. RESULTS: There were 480 extremities (74%) with a limb malformation including 184 involving the entire limb. Arthrogryposis was the most common of these (53 extremities). Anomalies affecting only the hand plate accounted for 62% (296) of the malformations. Of these, radial polydactyly (15%) was the most common specific anomaly, followed by symbrachydactyly (13%) and cleft hand (11%). Dysplasias were noted in 86 extremities; 55 of these were multiple hereditary exostoses. There were 87 extremities with deformations and 58 of these were trigger digits. A total of 109 children had a syndrome or association. Constriction ring sequence was most common. The OMT was straightforward to use and most anomalies could be easily assigned. There were a few conditions, such as Madelung deformity and symbrachydactyly, that would benefit from clarification on how to best classify them. CONCLUSIONS: Malformations were the most common congenital anomalies in the 653 upper extremities evaluated over a 1-year period at 3 institutions. We were able to classify all individuals using the OMT classification system.