The evolution of Charnley low-friction arthroplasty highlights the scientific basis for the operation. Long-term results show that the quality of pain relief remains excellent. The quality of the socket fixation has been improved by the use of new methods and designs, while a new technique of stem fixation has all but eliminated the loosening. Ultimately, wear and creep of the high-density polyethylene socket must be given serious consideration. Low friction remains the sound concept, and trochanteric osteotomy, now incorporating an element of compression in its reattachment, remains the method of choice for the exposure.