BACKGROUND Chronic rhinosinusitis with nasal polyps (CRSwNPs) has several phenotypes. OBJECTIVE The goal of this study was to evaluate computed tomography (CT) findings associated with each CRSwNP phenotype. METHODS Patient charts between January 2015 and March 2019 were retrospectively reviewed. Patient groups, including allergic fungal rhinosinusitis (AFRS), aspirin-exacerbated respiratory disease (AERD), central compartment atopic disease (CCAD) and CRSwNP not otherwise specified (CRSwNP NOS), were determined by standard criteria. The oldest CT scan available was reviewed for Lund-Mackay (LM) score, septal involvement of inflammatory disease, opacification of olfactory clefts, nasal cavity opacification, and oblique positioning of the middle turbinates. Nonparametric analyses of variance were performed with correction for multiple comparisons. RESULTS A total of 356 patients had scans available for review; 80 (23%) patients were categorized into the AFRS group, 101 (28%) in the AERD group, 43 (12%) in the CCAD group, and 132 (37%) in the CRSwNP NOS group. Septal inflammatory involvement and oblique middle turbinate orientation on CT scans was higher in both AERD patients and CCAD patients as compared to AFRS and CRSwNP NOS patients (P < .05). Olfactory cleft opacification was increased in the AERD group compared to all other diagnoses (P < .05). The CCAD group showed lower LM scores compared to all other groups (P < .05), and the AFRS group revealed the greatest differences between left and right LM grades, representing unilaterality of disease (P < .05). CONCLUSIONS CRSwNP encompasses many subsets of disease, which have varying treatments and intraoperative findings. Preoperative CT findings can be used to differentiate between these groups to improve prediction of diagnoses and patient counseling.