Psoriasis is a chronic inflammatory disease often associated with serious cardiovascular comorbidities. The aim of this study was to investigate the systemic inflammatory burden in psoriasis by examining various inflammatory markers and to assess the relationship between these markers and the severity of the disease. This retrospective study was conducted on medical records of patients who visited the dermatology outpatient clinic between 1 January 2016 and 31 December 2022. The study included patients with psoriasis vulgaris and healthy volunteers. Demographic data, Psoriasis Area and Severity Index score, C-reactive protein, monocyte-high-density lipoprotein cholesterol ratio, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, systemic immune-inflammation index, and Systemic Inflammation Response Index were analysed and compared. A total of 278 psoriasis patients and 90 healthy volunteers were analysed. Compared to the control group, psoriasis patients showed significantly higher systemic immune-inflammation index, Systemic Inflammation Response Index, neutrophil-to-lymphocyte ratio, monocyte-high-density lipoprotein cholesterol ratio, serum C-reactive protein levels, neutrophil count, monocyte count, body mass index, and waist circumference (p < 0.001, p = 0.001, p < 0.001, p = 0.014, p < 0.001, p < 0.001, p = 0.046, p < 0.001, and p = 0.011, respectively). Among patients with severe psoriasis (Psoriasis Area and Severity Index >10), systemic immune-inflammation index, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and serum C-reactive protein levels were significantly higher compared to patients with mild/moderate psoriasis (Psoriasis Area and Severity Index ≤10). In the ROC curve analysis, the optimal cut-off (AUC, sensitivity, specificity) values for neutrophil-to-lymphocyte ratio, systemic immune-inflammation index, and platelet-to-lymphocyte ratio were found to be 2.11 (0.592, 62%, 57%), 552.9 (0.579, 61%, 58%), and 111.9 (0.578, 64%, 46%), respectively. The inflammatory parameters that showed correlation with Psoriasis Area and Severity Index were systemic immune-inflammation index, Systemic Inflammation Response Index, neutrophil-to-lymphocyte ratio, monocyte-high-density lipoprotein cholesterol ratio, monocyte-to-lymphocyte ratio, and C-reactive protein. The findings of this study suggest that systemic immune-inflammation index, Systemic Inflammation Response Index, neutrophil-to-lymphocyte ratio, monocyte-high-density lipoprotein cholesterol ratio, and C-reactive protein values have the potential to serve as simple and cost-effective markers for assessing the inflammatory burden in individuals with psoriasis.