Objective[|]We aimed to measure the femoral trochlear cartilage thickness using musculoskeletal ultrasound (US) and examine the effects of cartilage characteristics on the quality of life and functional status in postmenopausal women diagnosed with knee osteoarthritis (OA).[¤]Materials and Methods[|]We examined 42 female patients and included a control group comprising 21 healthy women with similar age. Cartilage thickness, clarity, and subchondral bone calcification were evaluated using US with 5–13-MHz linear probe; pain and functional status were evaluated using the Western Ontario and McMaster Universities (WOMAC) OA index; and the quality of life was evaluated using Short Form-36 (SF-36).[¤]Results[|]A positive correlation was observed between measurements of 25-OH vitamin D levels and left intercondylar region, left lateral condyle, and right intercondylar area (r=0.416, p=0.006; r=0.421, p=0.001; and r=0.398, p=0.031, respectively). The quality of cartilage clarity was better in the patient group than in the control group for both knees (p<0.05). Cartilage clarity scores of the patients were positively correlated to the WOMAC total score and negatively correlated to the SF-36 total scores (left knee, r=0.159, p=0.314; right knee, r=0.261, p=0.096 and left knee, r=−0.263, p=0.093; right knee, r=−0.312, p=0.044, respectively).[¤]Conclusion[|]Compared with cartilage thickness, cartilage clarity appears to be a very successful parameter in reflecting the patient’s quality of life and functional status.[¤]