Malignant pericardial effusion is an uncommon disorder and is usually caused by far advanced lung cancer, breast cancer, lymphoma and leukaemia. Pericardial effusion in recurrent gastric cancer has been reported in only three patients. We report the case of a 53-year-old male with sudden onset of dyspnoea, pericardial effusion and cardiac tamponade and the unexpected and the asymptomatic concurrence of gastric cancer. Recurrent haemorrhagic pericardial effusion with physical signs of cardiac tamponade as the initial and only clinical manifestation of gastric cancer has not been described previously.