Abstract: Gastrointestinal cancer is the second most common cancer in Asia and second leading cause of death worldwide. It is a leading cause of cancer associated mortality. Hence, there is a need for early detection of GI cancer. Narrow band imaging (NBI) is a novel technology that enhances visualization of the vascular network and surface texture of mucosa, thereby assisting in tissue characterization, differentiation and diagnosis. NBI is used in early detection of inflammatory and neoplastic lesions of esophagus, stomach and large intestine.