Although bleeding into the intestinal lumen may occur in strangulating intestinal obstruction, haematemesis is infrequently encountered. We report on a patient who presented with haematemesis and who had, in addition, clinical and radiological features of small bowel obstruction. Upper gastrointestinal endoscopy did not locate the source of bleeding. At laparotomy, which was performed because of clinical deterioration, gangrenous strangulated small bowel secondary to adhesive obstruction was found. In a patient with non-resolving intestinal obstruction, a deterioration in the condition is a clear indication for exploration. Haematemesis occurring concurrently may be a marker of intestinal strangulation, adds strength to the indication and highlights the urgency of the need for exploration.