Congenital thumb anomalies are common and have a major impact given the specific functional role of the thumb. They may occur alone or as part of a multiple congenital anomaly syndrome. The primary goal of surgical management is to improve or restore pincer grip. In patients with ‘congenital’ trigger thumb, the A1 pulley must be released if the interphalangeal joint remains in fixed flexion. Thumb duplication is generally managed by reconstruction of the thumb from the predominant (ulnar-based) digit; the accessory (radial-based) digit is excised after collection of its tissue components needed for the reconstruction programme. Thumb aplasia requires pollicisation of the index finger by island flap transfer of the second ray to give it the shape, position, and function of a thumb. Among patterns of digital hypoplasia, some require reconstruction of the existing thumb and others excision of the rudimentary thumb followed by pollicisation. In patients with aplasia of multiple hand digits, a toe transfer may be considered when there is no natural tendency to develop digital prehension at the hand.