Many hypotheses have been proposed for the development of schizophrenia, including the one proposing that exogenous and endogenous factors are linked to inflammatory processes. There is strong evidence about the immunological and inflammatory dysfunction in schizophrenia. In this study, we aimed to measure serum 15-deoxy-delta(12,14)-prostaglandin J (15d-PGJ), peroxisome proliferator-activated receptor gamma(PPAR gamma), prostaglandin E2 (PGE2) and C-reactive protein (CRP) levels. Forty-four patients and 39 healthy volunteers were included in the study. Serum PGE2, 15d-PGJ, PPAR gamma and CRP levels were measured in both the groups. Demographic data forms were filled out for the patient group, and the Positive and Negative Syndrome Scale, Clinical Global Impression-Severity scale and Calgary Depression scale were used to assess patients' clinical status. Serum PGE2, 15d-PGJ and PPAR gamma levels were found to be significantly lower in patients with schizophrenia than in healthy controls. There was no significant relationship between the serum PGE2, 15d-PGJ and PPAR gamma levels and CRP levels.In this study, the evidence of systemic inflammatory conditions in patients with schizophrenia was found. The duration of the disease has been found to be the only variable that independently affects all three biomarker levels in the patients with schizophrenia.