Objective: Malignant peripheral nerve sheath tumors (MPNSTs) are rare soft tissue sarcomas with poor prognosis. The treatment options, especially in metastatic cases, are limited. In this study, we aimed to investigate the treatment outcomes along with programmed death-ligand 1 (PD-L1) expression as a potential surrogate for immunotherapy benefit in our patients with MPNST. Material and Methods: In this retrospective study, 27 patients diagnosed with MPNST and treated at the Hacettepe University Cancer Institute between 2000 and 2016 were evaluated. Patient and tumor characteristics, survival data and treatment modalities were obtained from medical charts. The patient outcomes were assessed based on the treatment modality. Slides prepared from 4-mm diameter microarray tissue were stained for the PD-L1 antibody using Leica Bond Autostainer (Cell Signaling, E1L3N®). Membranous staining more than 5% of the cells were accepted as positive. Results: The median age of the patients was 36 years (range 19-89 years), and 37% of patients were male. The median tumor size was 8.7 cm, and 62% of patients had high-grade tumors. The most common tumor localizations were extremities (41%), trunk (48%), and the headneck region (11%). Only two patients (7%) had distant metastases at the time of diagnosis. Seven patients (26%) had neurofibromatosis type 1 (NF1) and the presence of NF-1 was associated with partially worse overall survival (p=0.056). The majority of the patients underwent primary surgery (96.3%), and R0-R1 resection was achieved by 76% of patients. The median follow-up was 16 months (range 1 to 178 months). During the follow-up, 16 patients (59%) had recurrence (37% local, 22% distant recurrence). A 3-year disease-free survival (DFS) rate according to R0-R1 and R2 resection was 57% vs. 17%, respectively (p<0.001). After surgery, 48% of the patients received adjuvant therapy. Two patients (7%) received only chemotherapy, five patients (19%) received only radiotherapy (RT), and six patients (22%) received both. Patients who received both chemotherapy and RT had longer DFS compared to those who received either therapy alone and to those who received no adjuvant therapy (3-year DFS 100% vs. 14% vs. 44%, respectively, p=0.003) (Figure 3). PD-L1 expression was positive in 6 of 15 patients (40%) and was not associated with DFS. Conclusions: Multimodality treatment with surgery, chemotherapy, and RT may improve DFS in patients with MPNSTs. The PD-L1 expression is not associated with DFS.