There is a small group of patients with cerebral palsy who can be benefited by reconstructive surgery on the upper extremity, in addition to the usual therapeutic measures of splinting and muscle re-education. In cerebral palsy longstanding muscle imbalance, which can be improved only by surgical treatment, may prevent a hand from reaching its full potential for function. A group of case reports is presented of patients on whom several selective procedures, including arthrodesis, tenodesis, and tendon transfers have been performed. The intrinsic-plus or swan-neck deformity in cerebral palsy is described and illustrated with an analysis of the causative factors involved. It has been observed that the swan-neck deformity is caused by excessive tension on the middle band with relative relaxation of the lateral bands of the extensor mechanism. The tension on the middle band may come from the long extensors or from the intrinsics by way of their connection through the medial interosseous band or a combination of these forces. Prevention of the deformity is stressed and a method of surgical treatment is presented.