We have recently treated a child with prune belly syndrome in association with exomphalos and anorectal agenesis. This case raises the total incidence of exomphalos and anorectal agenesis to four and five, respectively, in our series of 13 cases of prune belly syndrome. Our case report lays emphasis on the severe respiratory problems that can complicate surgery in prune belly patients. We also attempt to relate the pattern of anomalies in our series to the controversy surrounding the embryogenesis of prune belly syndrome and suggest that our case material lends support to the concept of prune belly syndrome being due to an early disturbance of mesodermal development in both the abdominal wall and the urinary tract. We also suggest that the reported occurrence of gastroschisis in association with prune belly syndrome adds weight to the unifying theory of the embryogenesis of gastroschisis and exomphalos.