Twenty adult mongrel dogs underwent free jejunal transplants to the neck; 10 either died of or had to be sacrificed as a result of postoperative complications, 5 received a 55-Gy-equivalent dose of radiation after 3 weeks, and 5 were followed as controls. Serial manometric and endoscopic evaluations were performed over a 9-month period. Progressive deterioration of the quality and amplitude of peristalsis of the jejunal autografts was observed only in the radiated group. In addition, all dogs in the radiated group developed severe jejunal circumferential constriction and stricture formation. These delayed effects of irradiation on revascularized jejunal autografts should be considered in planning the method of pharyngoesophageal reconstruction as well as the timing of adjuvant radiotherapy.