The role of carcinoembryonic antigen (CEA) in Parkinson's disease (PD) has not been previously investigated. The aim of the present study was to evaluate the serum level of carcinoembryonic antigen, high-sensitivity C-reactive protein (hs-CRP), and Neutrophil/lymphocyte ratio (NLR) among patients with Parkinson's disease and to examine the relationship between these inflammatory markers. The cross-sectional design includes 51 patients with Parkinson's disease and 50 age- and sex-matched healthy controls. We investigated the differences in hs-CRP, CEA, and NLR levels between these two groups. CEA was significantly higher in PD patients relative to the control group (mean 2.40 ± 1.51 vs. 1.72 ± 0.87 (ng/mL), respectively; p = 0.015). Mean NLR was significantly higher in PD patients relative to the control group (mean 3.1 ± 1.3 vs. 2.1 ± 0.32, respectively; p < 0.001). Serum level of hs-CRP was higher in PD patients than in control group (mean 1.04 ± 0.62 and 0.54 ± 0.31, respectively; p < 0.01). Correlation analysis revealed significant correlation between hs-CRP, CEA, and Neutrophil/lymphocyte ratio (p < 0.05). This study demonstrates for the first time the association between CEA, hs-CRP, NLR, and PD. We found CEA, hs-CRP, and NLR levels to be significantly higher in the PD patients than in the normal controls.