The present study was aimed to assess the functional capacity of patients with low back pain (LBP) and to correlate the measured scores and parameters with various clinical and radiological data. Fifty patients with LBP were divided into 3 subgroups (16 post-laminectomy, 16 with disc lesions and 18 with spondylosis) were subjected to RMQ, Von Korff disability and pain scales and selected physical performance tests. The study showed significant differences between patients and controls regarding the physical tests, good correlation between VK disability, VK pain score and RMQ. Also, patients with limited lumbar flexion and those with disc lesions showed worse disability parameters than others. There were moderate correlation between questionnaires and PPT. The unique perspective each method provides appears to be useful for a better understanding of physical function in LBP patients.