This study was done to how Anatomical Variation Of lateral Wall of the Nose responsible for chronic sinusitis. 40 patients with chronic sinusitis were enrolled into this study. However, patients with allergic sinusitis, vasomotor sinusitis, atrophic sinusitis, nasal trauma and previous h/o of nasal surgery were excluded. All patients underwent clinical examination, diagnostic nasal endoscopy & CT PNS Coronal view. The frequency of occurrence of the sinonasal anatomical variations were Skull base type-keros type-ll 62.5% septal deviation in 65%, septal spurs in 47.5%, agger nasi cells in 72.5%, frontal sinus absent in 6.25%, frontal sinus hyperneumatisation in 27.5%, frontal recess obstruction in 18%, frontal cell showed type 1 cell in 6%, type 3 cell in 2%, and type 4 also in 2% cases. No type 2 cells were seen, paradoxical middle turbinate in 8.75%, pneumatized middle turbinate in 30% superior attachment of uncinate process to middle turbinate in38.75%, medialized uncinate process in 36.25%, pneumatised uncinate process in 2.5%, ethmoidal bullahyperplastic in21.25%, hypoplastic in 16.25% supraorbital cells in 22.5%, accessory maxillary ostia in 15%, Haller cells in 3.75%, pneumatised superior turbinate in 6.25% and Onodi cells in 22.5%,. varitation of sphenoid sinus ostia -circular in 30.6%, oval in 45.2% and slit like in 24.2%, pneumatisation of sphenoid sinus -presellar in 22.5%, sellar in 72.5%, conchal in 2.5% and absent in 2.5 %.large inferior turbinate in 36.2% and Rathke's pouch remnant in 2.5%.