Tehran University of Medical Sciences Iranian Journal of Psychiatry 1735-4587 16 3 2021 06 07 370 373 Tevfik Kalelioglu Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, Virginia, United States of America. Guler Celikel Department of Psychiatry, Bakırköy Mental Health Research and Teaching Hospital, Istanbul, Turkey. Ozlem Balaban Department of Psychiatry, Bakırköy Mental Health Research and Teaching Hospital, Istanbul, Turkey. Nesrin Karamustafalioglu Department of Psychiatry, Bakırköy Mental Health Research and Teaching Hospital, Istanbul, Turkey. Jennifer Kim Penberthy Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, Virginia, United States of America. 2019 03 11 Objective: Neuroleptic malignant syndrome (NMS) is a rare but severe side effect of antipsychotic medication. Neutrophil-lymphocyte ratio (NLR) is a simple marker used to measure systemic inflammation. Method: In this case report we explore the relationship of inflammation in the etiology of NMS. In our case involving NMS, although there was no leukocytosis, the NLR was increased up to systemic infection levels. Conclusion: We hypothesized that systemic inflammation may take a role in developing NMS. If so, NLR could be a new marker of NMS that may be able to provide more sensitive results than leukocyte levels.   https://ijps.tums.ac.ir/index.php/ijps/article/view/1714 https://ijps.tums.ac.ir/index.php/ijps/article/download/1714/1018