Objective: The assess of frequency anatomical variations of the frontal sinus coinciding chronic rhinosinusitis. Patients and methods: 80 patients with bilateral chronic rhinosinusitis not associated with nasal polyps. They underwent endoscopic sinus surgery from the period of Jan.2014 till Jan 2017 in otorhinolaryngology department Helwan and Benha university Hospitals . Results: CT scans extended from the frontal sinus to the sphenoid sinus. The slice thickness had been set at 4mm to evaluate the details of radiological findings. Studying CT scan of the patient is the core of this study mainly frontal sinus variations in all 80 patients (160 ) sidesof the frontal cell either type I, type II, type III, or type IV. And the last variant we investigated the frontal sinus drainage either medial or lateral to the superior connection of the uncinate process. Conclusion: Variation of frontal cells and the Agger nasi may contribute in chronic rhinosinusitis due to the complex of frontal recess ,which will need a more extended studies.