Aim: To evaluate the prevalence of Haller cells and the association between their existence and size of these cells with maxillary sinusitis and orbital floor dehiscence on cone beam computed tomography (CBCT) scans. Materials and methods: This was a retrospective study conducted on 300 CBCT scans with 200 ×170 cm field of view (FOV) taken for various purposes like implants and temporomandibular joint (TMJ) analysis. The CBCT scans and demographic details, such as age and gender of the patients obtained from the institution’s Digital Imaging and Communications in Medicine (DICOM) archive folder. The scans were checked for the presence of Haller cells, maxillary sinusitis, and orbital dehiscence. Chi-square test was used to assess the association between Haller cells and maxillary sinusitis and orbital dehiscence and p-values of 0.05 were considered to be statistically significant. Results: A statistically significant association was noted between the existence of Haller cells and maxillary sinusitis. There was no statistically significant difference in the mean size of the Haller cells between both the groups, although the greater number of medium and large size Haller cells are noted in the population with sinusitis. Orbital dehiscence and Haller cells have shown statistically significant association. Conclusion: The explanation of maxillary sinusitis based on mechanical obstruction is likely. This study provides evidence for the usefulness of CBCT scan in delineation of the sinonasal anatomy.