Background: The revolutionary changes in the surgical treatment of sinusitis in recent years, particularly in endonasal endoscopic surgery require the clinician to have precise knowledge of nasal sinus anatomy. Materials and methods: This study was undertaken on 100 normal paranasal sinus CT images (50 male & 50 female) in the age group of 20 to 70 years. The different dimensions like Antero–posterior diameter, Height and Width were measured. Results: In our present study, there was a significant increase in width of frontal sinus in males on right side and height of frontal sinus in males on left side. Conclusion: The sound knowledge of frontal sinus morphometry and variability is very useful to plan surgical approach to frontal sinus and also in medico–legal issues.