Trigger point treatment in myofascial pain syndrome should be planned according to its etiology to prevent relapses. Although there are various modalities, in cases where medical and noninvasive methods are ineffective, diluted local anesthetic injections or diluted local anesthetic injections with steroids, and sometimes dry needling or botulinum toxin, are preferred. In recent years, imaging methods such as ultrasonography have been frequently used for trigger point injections. These injections may be repeated for several sessions depending on the patient's response. Pain, local anesthetic toxicity, bleeding, allergic reactions, pneumothorax, intramuscular hematoma, cerebrovascular events, spinal injury, vasovagal syncope and infections have been reported during injections. Therefore, during trigger point injections, vascular access should be established in the patient, the patient should be monitored, injections should be performed under sterile conditions, and an emergency kit should be kept ready in all cases . The serratus posterior superior muscle is located deep to the rhomboid major and minor. Ligamentum nuchae starts from the processus spinosus of C7-T3 vertebrae and extends to the 2nd-5th. In the ribs, the angulus ends at the upper edge of the rib. Serratus posterior superior -intercostal plane block (SPSİPB) is a newly defined block, and C7-T7 spread has been shown in cadaver studies . In our study, investigators compared the newly defined SPSİPB, which is practical to be applied with USG in Myofascial Pain Syndrome (MAS), which is frequently seen especially in young people and desk workers, with trigger point injection, which has been used in the treatment of MAS for many years and whose effectiveness has been proven, and SPSİPB applied from a single point with USG guidance. investigators aimed to contribute to the literature regarding the effectiveness of in MAS. The newly defined rhomboid intercostal plane block and SPSIPB are routinely applied successfully in our algology clinic in patients with MAS and postzoster neuralgia in the thoracic region.