Purpose: Knee osteoarthritis is highly prevalent in the general population and causes significant knee pain and malfunction. Effect Effect of of age on the relationship between knee pain also knee function had not been studied in Egypt and had not been found in the literature. This research aimed to explore the relationship between knee pain also knee function in the Egyptian population with knee osteoarthritis-related pain and to determine the effect of age on this relation. Methods: This cross-sectional study involved seventy-eight patients having knee osteoarthritis-related pain aged from 40 to 80 years old. They were evaluated for their knee pain severity by visual analogue scale (VAS) also knee function by aggregate locomotor function scale (ALFS). Pearson correlation coefficient was calculated. Results. There was a significant direct weak correlation between knee pain also knee malfunction (r-0.32, p=0.004) that was retained only in older Egyptian patients having knee osteoarthritis-related pain (r=0.38, 0-0.015). Conclusions In Egyptian patients having knee osteoarthritis-related pain who are younger than 60 years old, knee pain is not related to knee malfunction, and they keep working despite the pain. So, in this population, the level of knee malfunction does not accurately reflect the level of knee pain or disease severity. This is to be considered during the assessment of the impact of knee osteoarthritis and the outcome measures of the interventions.