Highly detailed pathologic morphology of 25 knees with suspected structural abnormalities was depicted in thin-section, high-resolution magnetic resonance images (MRI) produced with the aid of a specially designed solenoid surface coil. Scans were obtained on a 0.3-T permanent magnet system with 4-mm-thick slices and 0.75-mm pixel size. The images were correlated with clinical, arthrographic and/or bone scan, and surgical findings. In 10 of 11 cases of clinically suspected meniscal tears, the MRI findings corresponded with those of arthroscopy. In the three cases of clinically suspected injury to the anterior cruciate ligament which underwent surgery, the MRI findings of tears in two cases and a normal ligament in one case were confirmed. MRI was also useful in the evaluation of possible injury to the patellar tendon, in the detection of intraarticular loose bodies, and in the diagnosis of osteonecrosis.