Aims: Degradation of articular cartilage in gonarthritis seems to be modiþable pharmacologically. For these to be helpful, early diagnosis is essential. Weight bearing radiograms obtained at various degrees of ßexion, have shown to provide more information about joint space narrowing (JSN). Methods: Between March and November 2001, 28 consecutive patients whom have been admitted to hospital for knee surgery due to knee osteoarthritis, enrolled for study. Their mean age was 57.5 years (in range of 35–78). Extension weight bearing A/P, lateral and tangential views were made on standard examinations. 30û Flexion standing P/A, and at 45û ßexion standing P/A knee xÐrays were made with the consent of patient. Surgical þndings of the cartilage (Outerbridge classiþcation) were compared with radiological þndings. Results: The statistical evaluations revealed that there is no signiþcant correlation between JSN and observed clinical osteoarthritis level at MFC, LFC, and LTP. A signiþcant correlation was found between the degree of JSN measured at weight-bearing A/P, 30û ßexion P/A and 45û ßexion P/A radiographs and the degree of cartilage degradation at MTP (p< 0.05). The semifelxion radiograms were found to demonstrate Conclusions: Radiograms taken at weight-bearing semißexed positions are more effective than standing A/P knee x-rays, in demonstrating the JSN, and JSN þnding is associated only with the medial compartment gon-arthritis. We concluded that the degree of ßexion (30û–45û) during radiographic examination is not an important factor and for the evaluation of the lateral compartment new positions should be deþned.