Surgical interventions for the spastic upper extremity secondary to stroke, traumatic brain injury, and cerebral palsy aim to correct the common deformities of elbow flexion, forearm pronation, wrist and finger flexion, ulnar deviation, and thumb-in-palm deformity. After appropriate evaluation, as well as determining the goals of surgery, deformity correction can be achieved through single-event, multi-level surgery. Surgery includes a combination of soft tissue lengthening, tendon transfer, and joint stabilization procedures. Surgical treatment for shoulder adduction/internal rotation, elbow flexion, forearm pronation, wrist flexion, thumb-in-palm, and clenched fist deformities due to spasticity are discussed, and treatment outcomes are reviewed.