Correlation between arthroscopic findings and preoperative radiographic studies (plain radiographs and arthrotomograms) was performed in a consecutive series of 37 elbows. Arthrotomograms added significant diagnostic information unavailable from plain radiographs alone, thereby improving the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic efficiency (accuracy) in the evaluation of elbow joint surface changes, marginal spurs, and loose bodies. Arthrotomograms gave 85% accuracy for bone spurs, 89% accuracy for joint surface abnormalities, and 89% accuracy for loose bodies (88% accuracy overall), whereas plain radiographs demonstrated 69% accuracy for bone spurs, 71% accuracy for joint surface abnormalities, and 75% accuracy for loose bodies (72% accuracy overall). The arthrotomograms had 100% sensitivity for loose bodies as well as a 100% negative predictive value for loose bodies. Arthrotomograms are indicated when additional preoperative diagnostic accuracy is necessary. These radiographic studies approached only 90% accuracy, confirming that diagnostic arthroscopy adds additional information.