Introduction.Although the popularity of platelet-rich plasma treatments has recently increased, physiotherapy is still one of the recommended methods of gonarthrosis treatment. The aim of the study was to examine the preferability of lower-cost physiotherapy compared with high-cost platelet-rich plasma treatment for gonarthrosis and the effects of both treatments on pain, functionality, and kinesiophobia. Methods. overall, 61 women participated in this randomized controlled study. The first group (physiotherapy) received conservative physiotherapy treatment (hot pack, ultrasound, transcutaneous electrical nerve stimulation, manual therapy) and home exercises. The second group (platelet-rich plasma) underwent only a home exercise program. An isometric knee exercise, an isotonic knee exercise, and dynamic step exercises for the quadriceps femoris muscle were planned for the home exercises. Exercise program compliance was monitored by exercise diary and telephone calls every day. The patients were evaluated in terms of pain levels, physical limitations (WoMAC and Lysholm scales), and kinesiophobia (Tampa Scale for Kinesiophobia). data were collected 4 times (before treatment and in the 4 th , 8 th , and 12 th week). Results. The patients' average age was 60.92 ± 10.67 years. in both groups, there was a decrease in pain and WoMAC and Tampa scores, and an increase in Lysholm scores compared with the pre-treatment outcomes (p < 0.05). No between-group difference in these parameters was observed (p > 0.05). Conclusions. The scarce difference in the indirect comparisons of the groups in terms of pain, functionality, and kinesiophobia scores may indicate that the two treatment methods may be equally recommended.