The purpose of this study was to investigate the effects of craniofacial structure and nasal septal deviation on frontal sinus morphology 3-dimensionally. This study of anatomy, anthropology, morphology, and radiology included 74 dry skulls as study sample. The craniofacial measurements were made through conventional anthropometric methods by the use of calipers. The nasal septal deviation measurements were done by computerized software on photographs taken from frontal view. Frontal sinus volumes were estimated by the computerized tomography-based volumetry. The relationships between craniofacial structure, nasal septal deviation, and frontal sinus morphology were tested by linear regression and correlation analysis. The analysis of numerical variables and categorical variables within different groups was done by Mann-Whitney U/Kruskal-Wallis, and χ2 tests, respectively. There appeared a positive relationship between the dimensions of the frontal sinuses and the maximal cranial length and the nasal height especially on the left side (P < .05). However, after multivariate linear regression model for both factors was created, solely the nasal height kept being a positive factor for frontal sinus size as an independent variable. No statistical relevance was detected between the presence of metopic suture and frontal sinus morphology. Septal deviation itself affected frontal sinus morphometry, but the morphometry did not differ between the deviation side and the opposite side. In conclusion, the cranial structure does not affect the frontal sinus morphology but nasal structure affects. The true influences, among measured craniofacial elements, in relationship with the pneumatization of frontal sinus are appeared to be the nasal structure related.