Background: Osteoarthritis (OA) is by far the most common and debilitating form of arthritis which can be defined as a degenerative condition affecting the synovial joint. Osteoarthritis patients frequently complain of a dull aching sensation when moving. When utilized effectively, physical agents such as warm or cold therapy can help to combat the unpleasant process. Aim. This study aimed to evaluate the effect of cold rub gel, warm versus contrast therapy on pain and joint function in patients with knee osteoarthritis. Design: A quasi-experimental comparative research approach was used to achieve the study's goal. Setting: The research was carried out at the Orthopedic outpatient clinic, Helwan General Hospital, Egypt. Sample: 60 adult patients with unilateral knee osteoarthritis were chosen as a purposive sample. Tools: The data was collected using four different tools. tool I: A questionnaire for an interview. Tool II: Knee Injury and Osteoarthritis Outcome Scale (KOOS). Tool III: 0-10 Numeric pain rating scale. Tool IV: Observational checklist. Results: demonstrated that after using the cold rub gel, warm and contrast method of therapy, the overall knee symptoms score went from moderate to mild. But the contrast therapy had a significant effect in reducing knee symptoms and pain and improving joint knee function than the other methods. Conclusions: all of the three methods of therapy resulted in improvement in all knee symptoms and pain but the most appropriate method of treatment to relieve symptoms and pain was contrast therapy. Recommendation: the study recommended that Contrast therapy should be considered the most effective treatment option for relieving knee symptoms and pain in patients with knee osteoarthritis.