A community study of the prevalence of osteoarthrosis of the hip requiring total hip replacement in elderly people is reported. It was found that 5.6% of the population studied had symptoms suggestive of osteoarthrosis of the hip, or had been successfully treated for it. In particular, 0.7% of the survey group had already been operated upon for this condition, and a further 0.5% would have benefited from total hip replacement. An additional 1.3% of the persons studied needed this operation, but were unfit for surgery.