Prosthetic hip replacement is associated with certain complications which result in a painful hip. Many of these, e.g. prosthetic dislocation, fracture, trochanteric avulsion, and heterotopic calcification are easily diagnosed by conventional radiography. However, radiographic evaluation for infection and/or loosening of prosthesis as major complications requiring reoperation often contributes little to the resolution of the diagnostic problem. The authors made a comparative study of plain radiography and scintigraphy of 39 cases performed revision at Kyung Hee Univ. Hospital from Sep. `81-to Aug. `86. RESULTS : 1. In 39 revised prosthetic hip replacement, 26 cases of looseningwithout infection and 11 cases of infection were proven. 2. In loosening of prosthesis, plain radiography showed true positive rate of 76% ad true negative rate of 60%, and scintigraphy showed true positive rate of 75% and true negative rate of 95%. 3. In infection of prosthesis, plain radiography reveal d true positive rate of 55% and true negative rate of 96%, and scintigraphy revealed true positie rate of 100% and ture negative rate of 83%. 4. Scintigraphy and plain radiography were useful as complementary procedure in evaluating and diffenentiating loosening and/or infection of prosthetic component.