Massive gastric tube dilatation causing cardiomediastinal tamponade is an unusual cause of obstructive shock after transthoracic oesophagectomy. A 55-year-old female was operated for total transthoracic oesophagectomy. Twelve hours after the surgery, she developed hypotension and raised central venous pressure unresponsive to fluid infusion and ionotropes. X-ray chest showed a massively dilated stomach, which was causing intrathoracic tamponade. Suction applied to the nasogastric tube led to aspiration of 150-200 ml of fluid and a large volume of air, which led to resolution of the haemodynamic instability. A simple manoeuvre like nasogastric suction in postoperative case of oesophagectomy can serve as a diagnostic as well as therapeutic tool. It must be performed before resorting to invasive and expensive examination or intervention.