Obscure gastrointestinal bleeding (OGIB) is a commonly encountered clinical problem in gastroenterology and is associated with significant morbidity and mortality. OGIB is classified into two types based on its presentation; overt and occult bleeding. Overt OGIB is bleeding that persists after negative endoscopic and radiological evaluation. Occult OGIB is iron-deficiency anemia with or without a positive fecal occult blood test. In patients with gastrointestinal bleeding, the underlying cause may not be evident on initial evaluation in 10–20% of cases. Endoscopy is used both as a diagnostic and therapeutic measure for gastrointestinal bleeding. This side set reviews the importance of endoscopy in overt and obscure GI bleeding.