Femoral condylar cartilage abnormalities were evaluated in patients treated with total knee arthroplasty, and real-time ultrasonic images were correlated with the abnormalities seen in the corresponding gross pathologic specimens. Subjective impressions of abnormalities on the images recorded on film correlated well with pathologic findings. Thickness measurements were easily made in normal images but proved difficult at sites of cartilage damage where the cartilage-bone and cartilage-soft-tissue interfaces became less clear. This study suggests that with further technologic refinement, this technique may provide a rapid and cost-effective method of assessing the integrity of femoral condylar cartilage.