Sonography is an imaging tool with many advantages while assessing the immature skeleton. In the last decade the Ponseti method of correcting clubfoot deformity by serial castings has gained terrain. By well-defined ultrasound (US) imaging projections the severity of the foot deformity can be assessed and its treatment monitored dynamically. Sonography can also be used in teaching how to perform the correcting manoeuvres properly. A reproducible US protocol for evaluating congenital clubfoot pathoanatomy, especially the talo-navicular and the calcaneo- cuboid joints, was developed. Normal configurations of the relationships at these joints were obtained by investigating healthy babies. Variations in clubfoot pathoanatomy are described. Morphological changes taking place during early clubfoot treatment, using the Ponseti method, were assessed and compared with a group treated by intensive physiotherapy and plexidur splint. The detailed descriptions of the sonographic protocol and its clinical implications should be useful to paediatric orthopaedic surgeons, physiotherapists, radiologist and other medical professionals treating and assessing clubfeet.