Subcutaneous venous port or ‘portacath’ devices are widely used, especially in oncology patients. Several potential complications of portacath devices have been well documented. We report a rare case of the spontaneous migration of the tip of a portacath into the azygos vein, with subsequent development of a tracheo-azygos fistula. This resulted in the patient receiving a dose of chemotherapy agent and saline directly into his lungs, which ultimately contributed to his death a few weeks later. To our knowledge, there have been only 10 previously reported cases of inadvertent intrathoracic (mediastinal, pleural or pulmonary) extravasation of chemotherapy agent as a result of central venous catheter malposition or perforation; this is the second reported case of extravasation of chemotherapy agent as a result of migration of a portacath device into the azygos vein.