An analysis is presented of employment of hyalgan (1% solution of hyaluronic acid) in 29 patients with osteoarthrosis of the knee joint (KJOA). The patients were divided into three groups. Group I comprized 9 patients with prior arthroscopic interventions in the knee joint with stage I KJOA; group II was 5 patients having undergone plasty of the anterior cruciate ligament with stage I KJOA; group III was 15 patients with stage II-III KJOA. Hyalgan (20 mg) was administered once per week for 5 weeks. Intensity of the pain syndrome was assessed by using a visual-analogue scale together with time-related thermal gradient with the aid of the remote infrared thermography technique. Hyalgan enhances efficiency of treatment of KJOA.