Abstract: Introduction: Variations in pneumatization patterns and frontal sinus ostium morphology complicate surgical navigation and management of frontal sinus pathology. This study aimed to evaluate the morphological characteristics of the frontal sinus in a South Asian population using computed tomography (CT) imaging, focusing on pneumatization patterns, frontal ostium diameter, and frontal ostium grading. Methods A retrospective review of 106 patients (212 frontal sinuses) who underwent CT scans of the paranasal sinuses at Aga Khan University Hospital, Karachi, Pakistan, was conducted. Data on frontal sinus pneumatization, frontal ostium diameter, and frontal ostium grading were analyzed. The study population had a mean age of 40.4 ± 14.4 years, with a male-to-female ratio of 2:1. Results: Our study revealed that the majority of patients (95.5%) exhibited medium pneumatization (Type 2), while aplasia/hypoplasia (Type 1) and hyperplasia (Type 3) were rare (2% and 3%, respectively). The mean frontal ostium diameter was 7.8 ± 2.0 mm on the left and 7.4 ± 2.1 mm on the right, with minimal gender-based differences. Frontal ostium grading showed that 81.1% of left-sided and 67.9% of right-sided ostia were classified as FOG-positive, indicating easier surgical access. Conclusion Our findings highlight that the population exhibited medium pneumatization (Type 2) of the frontal sinuses. The mean diameter of the frontal sinus ostia showed slight variations between genders and between the right and left sides, with overall averages of 7.8 mm on the left and 7.4 mm on the right.