Five children with popliteal webbing and flexion contractures of the knees are described. When their associated anatomical abnormalities are considered, classification into two distinct syndromes, multiple pterygium and popliteal pterygium, is possible and of importance in genetic counselling. Soft tissue surgical corrections of the flexion contractures were undertaken in each case. The operative technique, local abnormalities, and orthopaedic management are discussed.