There have been concerns about the relation between radiological and clinical symptoms in knee osteoarthritis (OA). The aim of this study was to compare the Kellgren-Lawrence (K/L) grading, semiquantitave osteophyte score (SOS), the medial joint space score in supine anteroposterior (AP) film of the extended knees (SupMJS), the medial joint space score in AP film of standing knees in semiflexion (StMJS), with pain, range of motion (ROM) and function in patients with knee OA. In 37 patients with knee OA, pain was evaluated with visual analog scale, ROM with goniometry and the function with Lequesne functional index (LFI). Pain with motion was higher, but the active and passive flexion ranges were less in grade 4 K/L patients when compared with earlier grades. All radiological criterias except SupMJS were in significant positive correlation with only motion pain while all radiological parameters correlated negatively with active flexion ranges. No significant correlation was found for other pain types and LFI. In lineer regression analysis only SOS was observed to have relation with motion pain (Motion pain score=3.757+1.064x SOS). It seemed to be wise to obtain AP films of standing knees in semiflexed position and take care of StMJS together with K/L classification and SOS in order to predict the motion pain in patients with knee OA.