The pathogenesis of maxillary sinus fungal ball (MSFB) is explained by aerogenic and odontogenic factors. We evaluated the predisposing factors, including intranasal anatomical and dental factors for increased diagnostic accuracy. In this study, 117 patients who underwent endoscopic sinus surgery for unilateral MSFB were included. Preoperative computed tomography (CT) scans were used to analyze the presence of anatomical variations (anterior and posterior nasal septal deviation (NSD), concha bullosa (CB), infraorbital cell (haller cell), paradoxical middle turbinate, everted uncinate process and MS size). Dental factors including history of dental procedures and findings on CT scans were reviewed. Anterior and posterior NSD toward non-affected side were significantly associated with the presence of FB. The presence of CB and infraorbital cell was higher in the non-affected side rather than in the lesion side. Compared to non-affected MS, FB-presence MS was shallower and had a larger height to depth ratio. The presence of dental history was significantly higher on FB-presence MS than non-affected MS. In multivariable analysis, posterior NSD toward non-affected side, dental history increased the aOR of MSFB, while the presence of CB and infraorbital cell decreased the aOR of MSFB. The occurrence of MSFB seems to be associated with ipsilateral odontogenic factors, followed by anatomic variations including posterior NSD toward non-affected side and absence of CB and infraorbital cell.