Objective: To assess the functional disability in knee osteoarthritis patients using aggregated locomotor function (ALF) score in correlation to clinical and radiological variables. Patients and methods: 43 patients, 22 females (51.2 %) – 21 males (48.8%), with a clinical diagnosis of knee osteoarthritis were included in the study. The mean age of the patients in the study was 58.0 ± 9.0 (yrs) with a range of 40.0 – 75.0 (yrs). All subjects fulfilled American College of Rheumatology (ACR) clinical criteria for knee OA (2004). Patients were excluded if they had traumatic or inflammatory arthritis or major concurrent illness. All patients were subjected to full history taking, clinical examination, radiological evaluation and functional assessment using the ALF score. Results: The mean time of the (ALF) score in the study patients was 43.58 ± 14.58 sec. with a range 23.92 - 80.42 sec. There was a significantly high ALF mean score in patients with muscle power grade 3 than those with muscle power grade 4 or 5, patients with score (2) tenderness than those with score (1) or (0) and patients with knee effusion than those without. There was a higher ALF score in patients with varus or flexion deformity than patients without deformity. Radiologically, patients with X - ray grade 4 had ALF mean higher than those with grade 3, 2 or 1. A significant positive correlation was found between ALF score and age (r=0.453**, P=0.002), weight (r=0.888 , P= 0.022), BMI (r=0.755, P=0.039) and VAS for pain (r=0.307* , P=.045). Conclusion: This study has demonstrated that a simple timed measure of locomotor function can be used as a measure of physical functioning. Knee OA patients with worse clinical condition (knee joint effusion, deformity, tenderness, weak quadriceps muscle strength, limited range of motion and high BMI) or more radiological damage revealed to be more functionally disabled and had high ALF score. The individual components of the ALF challenge the locomotor function of patients with knee OA, but are not so demanding that they cannot be completed. Consequently, the measure appears to offer the patient and clinician an appropriate, simple and convenient outcome measure in the treatment of knee OA.