Gastrointestinal stromal tumours (GISTs) are considered to derive from the interstitial cells of Cajal or their precursors and are defined by their expression of c-kit protein (CD117) that is positive in 95% percent of cases. These are rare mesenchymatous tumours, while they represent the most common mesenchymal tumours of the alimentary tract. The majority of GISTs develop in the stomach and small intestine and more rarely in the rectum, colon, esophagus and mesentery; only 3-5% of all GISTs are located in the duodenum. The presenting symptoms include early satiation, dysphagia, bloating, abdominal pain and gastrointestinal bleeding, either acute or chronic. Surgery remains the mainstay of treatment for localized, non-metastatic, resectable GISTs. We present a case of duodenal gastrointestinal stromal tumour of the third portion of the duodenum that presented with acute upper gastrointestinal bleeding treated with segmental duodenal resection.