BACKGROUND Chronic rhinosinusitis is one of the most commonly encountered diseases of ENT practice. It is characterised by inflammation of mucosa of nasal cavity and sinuses which does not respond to routine treatment up to 12 weeks. It is an extremely common condition affecting 15% population. It has been seen that the inflammatory sinus disease involves the maxillary and frontal sinuses with the underlying seat of pathology in the tissues of anterior ethmoids. Detailed definition of the syndrome was developed by rhinosinusitis task force of the American Academy of Otolaryngology-Head & Neck Surgery. For the diagnosis of chronic rhinosinusitis, patients were evaluated by anterior rhinoscopy, nasal endoscopy and CT paranasal sinus especially coronal cuts were preferred. After the development of nasal endoscopy, diagnosis of the nose and paranasal sinuses diseases were made easy by direct examination of nasal cavity and opening of paranasal sinuses as an OPD procedure. For defining the anatomical boundaries and any abnormality in the sinuses frame work CT scan has proven to be beneficial. The aim of the study was to diagnose chronic rhinosinusitis either by CT scan or endoscopic examination of nasal cavity and paranasal sinuses visa -vis is better. Nasal endoscopy has dramatically reduced morbidity and can avoid unnecessary radiation exposure, cost and time in Indian scenario as we have to deal with the poor people in daily practice. MATERIALS AND METHODS We evaluated 60 patients of age groups 10 years and above of chronic rhinosinusitis for 3 months or more by nasal endoscopy and CT scan of paranasal sinuses to know the value of both modalities and whether by avoiding CT scan we can avoid unnecessary radiation exposure, cost and time of investigations. RESULTS We had good results by both endoscopy and CT scanning of the patients of chronic rhinosinusitis in assessing the disease as perceived by other studies. The results of endoscopy and CT comparison among 60 patients indicated that for most of the findings there was almost perfect to substantial level of agreement between the two modalities. CONCLUSION Nasal endoscopy is also a good tool for direct visualisation and comparison of sinonasal disease and being an outpatient procedure may reduce unnecessary diagnostic CT scanning. It gives good vision with brilliant illumination of nose and paranasal sinuses. Thus, CT scanning should be reserved for refractory cases not responding to treatment and thereby reducing cost and radiation exposure.