To clarify the role of TNF-α, IL-18, osteopontin, lipoprotein (a) and paraoxonase in psoriasis in Iraqi community this study was conducted. Cross-sectional study included 94 subjects with psoriasis vulgaris, with a mean age of 37.5 ± 11.6 year. Serum osteopontin, IL-18 and TNF-α were determined using Enzyme linked immunosorbent assay kits. The mean serum levels of TNF-α, IL-18, OPN, and LP (a) were significantly higher in individuals with psoriasis as compared to controls. In contrast, PON 1 mean serum value was significantly lower in psoriasis compared to controls. Odd ratio indicated a significant association between increase in TNF-α, IL-18, OPN and Lp(a) and the decrease in PON1 in our cohort study. Disease severity significantly correlated with serum levels of TNF-α, IL-18 and Lp (a), while inversely correlated with serum levels of PON 1. TNF-α was with high predictivity in monitoring psoriasis severity and response to treatment. The elevation of serum IL-18, OPN, LP(a) and reduction of PON1 indicated that these biomarkers may play a role in psoriasis pathogenesis. The significant correlation of serum levels of TNF-α, IL-18 and LP (a) with PASI and inverse correlation of PON1 with PASI are useful biomarkers for monitoring of disease severity and treatment outcome.