Radioulnar synostosis is a rare disease which causes supination and pronation restriction as a result of osseous or fibrous connections between the radius and ulna. Radioulnar synostosis includes both congenital and post-traumatic types. Post-traumatic radioulnar synostosis can be seen in the proximal, middle, and distal part of the forearm, depending on the location of the trauma. Congenital proximal radioulnar synostosis occurs as a result of a separation defect between the radius and ulna in the embryonic period. In the presence of congenital proximal radioulnar synostosis, the patient should be evaluated for accompanying syndromes and possible developmental anomalies. In this report, we present a rare case of both proximal and distal radioulnar synostosis. Hypoplasia of the right pectoral muscle mass, hypoplastic appearance of the right nipple, presence of proximal and distal radioulnar synostosis in the right forearm, and accompanying symbrachydactyly suggested Poland syndrome. To the best of our knowledge this is the first case of congenital proximal and distal radioulnar synostosis with Poland syndrome.