Rosacea is a chronic inflammatory skin disease that is characterized by recurrent episodes of erythema, telangiectasia and papulopustular lesions. Although the pathogenesis is not well established, growing knowledge suggests that multiple etiological factors play a role resulting in inflammation. The aim of the present study is to investigate inflammatory status of patients with rosacea by evaluating CBC parameters and systemic immune inflammation (SII) index and compare these parameters with control group. Thus, it is aimed to understand the role of systemic inflammation in the pathogenesis of the disease. This retrospective, case–control study included 100 patients with rosacea and 58 sex- and age-matched controls. Laboratory examinations including CBC, ESR, CRP, HDL, LDL, and triglyceride levels were recorded and neutrophil–lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), and platelet-lymphocyte ratio (PLR), monocyte-to-high-density lipoprotein ratio (MHR) and SII index were calculated. Monocyte and platelet count, SII index, ESR and CRP were significantly higher in patients with rosacea than in the control group. No statistically significant difference was found in other parameters. There was no significant correlation between disease severity and ESR, CRP, and SII index. The findings of this study suggest that apart from the inflammatory pathways at the level of skin, there is an inflammatory state in the blood of patients. Rosacea is a skin disease, but it may have systemic implications and/or associations that need to be clarified completely.