This is an English translation of the original classic paper by Prof. Dr. H. Hilgenreiner in which he reviews the then (1925) current thought on congenital dislocation of the hip (CDH), argues for its early treatment, outlines techniques for early diagnosis, presents a splinting method of treatment for infants, and, especially, describes his method of radiographic evaluation, including the measure of acetabular development that has become known as "the acetabular index." His anticipation of our present understanding of CDH is surprising.