Gastrointestinal complications after cardiac surgery are uncommon, but are associated with a high morbidity and mortality. Over 11 years 8559 procedures requiring cardiopulmonary bypass were performed in this unit and 35 patients were identified who developed gastrointestinal complications after surgery, an incidence of 0.41%. There were nine deaths in this group, a mortality of 25.7% compared with an overall mortality after cardiac surgery in Ireland ranging from 3.24% to 4.81%. These complications required surgery in 21 patients. The most common indication for surgical intervention was upper gastrointestinal bleeding in 10 patients, three patients had acute pancreatitis, two patients had perforated peptic ulcer; two patients had intestinal ischaemia, with five cases of colon pathology. The difficulties of making an early diagnosis are outlined and a low threshold to exploratory laparotomy is recommended.