Objective: The release of neutrophil gelatinase-associated lipocalin (NGAL), involved with immunity regulation, is a neuromediators. The number of studies related to disease-hemogram in Obsessive Compulsive Disorder (OCD) is low. The aim of our study was to measure the blood NGAL levels and hemogram results in first diagnosis of OCD and to evaluate the relationship between the findings and disease severity. Methods: A total of 28,050 patients, who were presented to psychiatry outpatient clinic between January 2018 and January 2020 were evaluated. Thirty-two patients, for who were diagnosed first-episode OCD and agreed to participate the study were examined with using the Yale Brown Obsession Compulsion Scale (Y-BOCS), to measure the peripheral blood NGAL levels and hemogram results, and related to immune regulation the total leukocyte counts and neutrophil granulocyte percent-age (NEU%); and the C reactive protein (CRP) levels were recorded. Results: In the comparison of the first-episode OCD patients, a significant difference was found between the NEU% and CRP values while was not found between the blood NGAL levels. Although there was no significant difference between the Y-BOCS scores and blood NGAL levels, the Y-BOCS scores increased as the blood hemoglobin and hematocrit values decreased. Conclusion: This is the first study on this topic in the literature, indicated that although there was an increase in some inflammatory mediators in first-episode OCD patients, there was no significant increase between plasma NGAL levels and OCD severity; and that increasing OCD severity did have an effect on blood hemoglobin and hematocrit levels.