Background: Doubts have been expressed about the relationship between the severity of symptoms of osteoarthritis (OA) knees and anatomical changes within involved joints. Objective: To investigate characteristics of magnetic resonant images (MRI) of heavily symptomatic knees with OA. Methods: A prospective observational cross-sectional study was conducted on 54 symptomatic knees OA on admission. These patients were selected for MRI investigation. Results: 100 percent of the patients had cartilaginous defects, 53 percent had osteochondral defects, 74.1 percent had bone marrow edemas, 38.5 percent had subchondral cysts, 74.1 percent had osteophytes, 100 percent had meniscal intrasubstance degeneration, 42.6 percent had meniscal subluxations, 57.4 percent had meniscal tears, and 18.5 percent had portions of menisci loss, 90.7 percent had synovial effusions or synovitis. Conclusion: Anatomical changes in heavily symptomatic knees with OA are obvious.