Thiphalangeal thumb is characterized by interposition of an extraphalanx between the two normal phalanges of the thumb. The extra-phalanx varies from a small triangular bone to a normal phalanx in what appears to be a thumbless five fingered hand. Triphalangeal thumbs are divided into three types and the treatment differs from associated anomalies and clinical features. We had a bilateral triphalangeal thumbs treated by closed wedge osteotomy to the extra-phalanx.