Self-reported olfactory dysfunction is an assessment component criterion for chronic rhinosinusitis (CRS) disease control of the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS). No studies have objectively explored olfactory function across different psychophysical olfactory domains among patients with uncontrolled CRS. We aimed to investigate the patterns of olfactory impairment in patients with uncontrolled CRS with Sniffin' Sticks test.A total of 79 patients with CRS were prospectively recruited and assessed for disease control based on the EPOS criteria. Sniffin' Sticks test scores, olfactory cleft computed tomography (CT) scores, olfactory cleft endoscopy scale (OCES), questionnaire of olfactory disorders-negative statements (QOD-NS), and sinonasal outcome test-22 (SNOT-22) were obtained. Multiple logistic regression was applied to explore risk factors of uncontrolled CRS.Twenty-six percent of patients with CRS presented with uncontrolled status. The odor threshold (OT) (p = 0.005), odor identification (OI) (p = 0.041), and thresholds-discrimination-identification (TDI) (p = 0.029) scores were significantly lower in patients with uncontrolled CRS when compared with patients with controlled CRS. Furthermore, patients with uncontrolled CRS presented with a significantly increased percentage of anosmia (p = 0.014), olfactory cleft CT score (p = 0.038), OCES (p = 0.016), QOD-NS(p = 0.008), and SNOT-22 (p < 0.001) scores than patients with controlled CRS. After adjusting for patient demographics, as for the subdomain of olfaction, only the OT score was an independent risk factor for uncontrolled CRS (odds ratio = 0.604; p = 0.030). The OT scores less than 5.950 were the best predictor of uncontrolled CRS.Patients with uncontrolled CRS demonstrated distinct patterns of olfactory impairment, and a reduced olfactory threshold was highly associated with uncontrolled CRS.3 Laryngoscope, 2024.© 2024 The American Laryngological, Rhinological and Otological Society, Inc.