Abstract Background Psoriasis is a chronic systemic inflammatory disease frequently associated with serious comorbidities. Objectives To investigate the systemic inflammatory burden in psoriasis and to assess the correlation between traditional and novel inflammatory markers and the severity of the disease. Methods This cross-sectional study was conducted on 60 patients with psoriasis vulgaris and 50 healthy volunteers. Data including demographics, Psoriasis Area and Severity Index scores, and laboratory results were analyzed and compared. Results Compared with the control group, the psoriatic patients had significantly higher high sensitive C-reactive protein, serum amyloid A, erythrocyte sedimentation rate, leukocyte, neutrophil, neutrophil-to-lymphocyte ratio, monocyte to high density lipoprotein (HDL) cholesterol ratio, and aspartate aminotransferase levels, and significantly lower HDL cholesterol levels (p < 0.05). No significant difference was found in procalcitonin, lymphocyte, monocyte, hemoglobin, red blood cell distribution width, platelet, mean platelet volume, platelet distribution width, lymphocyte-to-monocyte ratio, anti-cyclic citrullinated peptide, glucose, alanine aminotransaminase, blood urea nitrogen, creatinine, triglyceride, total cholesterol, and LDL cholesterol levels between the two groups (p > 0.05). The Psoriasis Area and Severity Index score was positively correlated with high-sensitivity C-reactive protein, serum amyloid A, and monocyte to HDL cholesterol ratio, and negatively correlated with lymphocyte-to-monocyte ratio (p < 0.05). Study limitations This was a single-center study with relatively limited numbers of patients and controls. Conclusions The data show that high sensitivity C-reactive protein, serum amyloid A, erythrocyte sedimentation rate, neutrophil-to-lymphocyte ratio, and monocyte to HDL cholesterol ratio can be used as markers of systemic inflammation in patients with psoriasis. Moreover, high sensitivity C-reactive protein, serum amyloid A, monocyte to HDL cholesterol ratio and lymphocyte-to-monocyte ratio are closely related to the Psoriasis Area and Severity Index score, and they may be regarded as objective indicators in determining the disease severity.