Piriformis Syndrome (PS) is defined as a trap neuropathy that involves compression of the sciatic nerve by the piriformis muscle, leading to a number of symptoms along with sciatic pain, initially in the hip muscles. In clinical practice, it is estimated to be between 12.2-27%. Repetitive movements with increased demand on the piriformis muscle can lead to increased muscle tension, compression of the sciatic nerve within the muscle, and the development of PS. Additionally, the anatomical structure of the piriformis muscle and the alignment and damage of adjacent structures play a role in the pathophysiology of sciatic nerve compression in PS. It is considered in pathophysiology that a morphological change (contracture, hypertrophy) may cause compression of the sciatic nerve or the relationships of different anatomical structures that change with biomechanical restrictions. Pain is observed along the ipsilateral sciatic nerve distribution due to compression of the sciatic nerve. Additionally, it has been observed that patients with PS are accompanied by weakness in the gluteal muscles, mostly in the gluteus maximus and medius muscles. Accompanying weakness has an effect on static and dynamic posture (2,3). The negative effect of pain on posture has also been shown in studies (4). Pain and muscle changes in the lower extremities also cause disability and postural instability. It has been reported that static and dynamic postural balance is reduced in PS compared to healthy controls (1). Conservative treatment for PS significantly reduces pain with a wide range of therapeutic alternatives. Since ozone injection does not have side effects or major complications, its use in the treatment of myofascial pain syndromes and piriformis syndrome is supported by studies (5). It has an analgesic effect, increasing the pain threshold by activating serotonin-mediated pathways to release endogenous opioids. Additionally, it is used safely due to its low side effect profile. In the literature, it has been shown that local anesthetic injection applications alone or in combination with steroids are effective in the treatment of PS alone due to the therapeutic effects of local anesthetic (6). This study aimed to investigate the effects of ozone and local anesthetic injection on pain, functional level and posture in patients diagnosed with PS.