Objective: Sinonasal inverted papillomas are benign neoplasms of the nasal cavity and paranasal sinuses. They have characteristic features such as a high risk of recurrence and possible malignant transformation. This study was conducted to investigate the relationship between sinonasal inverted papilloma and inflammatory blood markers. Patients and Methods: Sixty-five patients who were diagnosed histologically as having sinonasal inverted papilloma and 65 age- and sex-matched healthy controls were included in the study. Inflammatory blood markers such as neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), red cell distribution width (RDW), mean platelet volume (MPV), and platelet distribution width (PDW) of the patient and control groups were compared. Results: There were no statistically significant differences between the patients and controls for white blood cell, platelet, hemoglobin, neutrophil, and lymphocyte counts (P > .05). No statistically significant difference was found between the patients and controls for NLR, PLR, RDW, MPV, and PDW (P > .05). In the logistic regression analysis model, which was created to investigate the effects of inflammatory blood markers in determining the patient group, the increase in the NLR and decrease in the PLR were found to be statistically significant factors (P = .008, P = .039). Conclusion: This is the first study in the literature to investigate the relationship between sinonasal inverted papilloma and inflammatory blood markers, and the results suggest that NLR and PLR may be used to distinguish patients with sinonasal inverted papilloma from controls.