A brief anatomy and the relationship of the paranasal sinuses to vital structures are shown through easily reproducible line diagrams. The mode of mucociliary flow mechanism in the sinuses is illustrated. Palpation of each sinus is demonstrated. X-ray PNS and CT paranasal sinuses: coronal and axial sections are shown. Predisposing Factors, Signs and symptoms of sinusitis and treatment plan is tabulated. Modes of spread and Complications of sinusitis is charted. Causes of facial pain are listed in a chart. Uncommon cases like frontal sinus mucocele, dental cyst, nasolabial cyst, cementifying fibroma are shown. It also depicts the benign and malignant tumor of paranasal sinus along with their CT films. Eyes and paranasal sinuses have close anatomical relationship and any pathology involving one may affect the other. A case of Blowout fracture of orbit with muscle entrapment with preoperative, postoperative pictures and CT scan is very well illustrated. Pictures of intranasal endoscopic DCR are also shown.