Few authors have studied differences in craniofacial morphology of adults with chronic otitis media (COM). We sought to compare the craniofacial measurements of patients with COM with otherwise healthy adults. The study group included 120 adult patients. The control group had 30 men and 30 women without evidence of otitis media; a COM group consisted of 30 men and 30 women with COM. Craniofacial measurements were assessed retrospectively using a two-dimensional reformatted CT method. Multiple linear (bony and cartilaginous auditory tube length, size of the mastoid, height of the jugular bulbus, intercochlear distance, bitemporal distance, distance between pharyngeal orifices, and some cephalometric cranial base distances), angular (auditory tube angle, cranial base angle), and area (axial and sagittal nasopharynx size) measurements were performed. In addition, petrosquamosal (Körner's) septum prevalence and size were evaluated. No statistically significant differences were found regarding craniofacial variables except mastoid size (mastoid depth and length). None of the craniofacial parameters showed significant differences between adults with COM and adults without evidence of otitis media, when age, sex, and race were considered. No statistically significant differences were found when mastoid size was compared with unilateral and bilateral COM. No statistically significant difference was found between mastoid size of the intact side and involved side of the unilateral patients with COM. Patients with unilateral and bilateral COM may be in the same group, genetically or environmentally, as far as mastoid size is concerned. Small mastoid size correlates with COM, but development of clinical disease should be under the control of different factors.