Background: Osteoarthritis (OA) is the most prevalent and far common debilitating form of arthritis which can be defined as a degenerative condition affecting synovial joint. Physical agents can fight the painful process such as cold or contrast hydrotherapy Aim. Evaluate the effect of cold application versus contrast hydrotherapy on pain control, functional abilities and quality of life. Setting: The study was conducted at Assuit University Hospital in out patients' clinics. Subjects: 180 adult patients with knee osteoarthritis. Tools: were selected four tools Tool I: Bio-socio demographic characteristics Tool II: 0-10 Numeric pain rating scale. Tool II1: health assessment questionnaire. Tool IV: WHOQOL-BREF Results: decreased mean of pain score between contrast group than cold group (3.5 ± 2.1 vs 7.0 ± 1.9 respectively, improve mean HAQ disability index score intervention was 17.9 ± 6.3 &12.7 ± 5.9 between cold and contrast hydrotherapy respectively and increasing mean between contrast group than cold group regarding all domain of quality of life. Conclusion: greater pain relief and functional improvements found when subjects used contrast therapy. Recommendation: Superficial contrast therapy should be included in the early effort to manage patients with osteoarthritis.