The utility of histological examination of tissue removed during elective joint replacement has not been determined. During a one-year period, tissue removed during 168 total joint replacements was submitted for histological examination. The clinical and histological diagnoses, the cost of the histological study, and the clinical course were determined for all joints. Degenerative joint disease, rheumatoid arthritis, and avascular necrosis accounted for 98 per cent of the histological diagnoses. There were sixteen discrepancies between the clinical and histological diagnoses. The histological diagnosis did not affect the treatment of fifteen of these joints. However, the treatment was altered for one joint that had a clinical diagnosis of degenerative joint disease and a histological diagnosis of osteomyelitis; on review, the initial histological diagnosis was determined to be incorrect. In 1996 dollars, the cost of histological examination for all 168 joints was $10,698.24. Although there would be considerable cost-savings on a population basis if histological examination were not performed, this savings must be weighed against the effect of a misdiagnosis on the management of a particular patient.