With the availability of upper GI endoscopy and CT scans, the indications for barium meal upper gastrointestinal (GI) study of the stomach and duodenum have declined. To a large extent, barium studies have been replaced by “Upper GI” (UGI) endoscopy and CT scans. However, they are still requested by paediatric surgeons and sometimes by GI and bariatric surgeons. Therefore, it is important to know how to perform it well, as well as know the appearance of the structures seen in an upper gastrointestinal series and what diseases as well as post-operative sequelae look like.