The purpose of this study was to compare the efficiency of intra articular hyaluronic acid and rofecoxib in patients with gonarthrosis. 39 patients were enrolled in the study (33 women, 6 men). In randomly  selected, 21 patients  intraarticular hyaluronic acid was applied once a week, 5 times and 18 patients were given rofecoxib 25 mg once a day for 5 weeks. Pain duration was recorded and radiological classification was made. At the beginning of the treatment and at the end of the 3 rd, 4 th and 5 th weeks spontaneous pain and activity pain was determined using VAS. The WOMAC was used to evaluate the functional capacity of the patients. There was no difference between the two groups according to  age, sex, duration of pain and radiological classification (p>0.05). In both treatment groups statistically significant improvement was determined in the VAS and WOMAC scores using variance analysis according to four evaluations made at four different times (p<0.001). There was no significant difference between two groups according to mean VAS values (p>0.05). Statistically significant improvement was found in the intraarticular HA group compared to the rofecoxib group by using WOMAC. Rofecoxib was more effective than HA in the 50 feet walking duration and stiffness according to WOMAC. As a result; both rofecoxib and intraarticular HA were effective in the treatment of pain in patients with gonarthrosis. Rofecoxib was more effective in 50 feet walking duration and stiffness, but intraarticular HA injection was more effective in improvement of the daily living activities and functional capacity.