Purpose. Formation of a tracheoinnominate artery fistula (TIF) and consecutive hemorrhage is a rare and life-threatening complication with high mortality. Warning symptoms can be absent. The current literature contains only few considerations for misleading signs, especially in cases where the contact between the tissue and the cannula is tight. Method and Results. We report two cases of life-threatening hemorrhages that appeared six days and two months after percutaneous dilatational tracheostomy (PDT) in two patients, respectively. In these cases, diagnosis of tracheoinnominate artery fistula (TIF) was difficult. Tracheal ring fracture after PDT and pressure ulceration caused by cannula were implicated in TIF formation. The cannula was overblocked to buy time before surgical closure. Both patients survived without any additional neurological deficiency. Conclusion. Massive hemorrhage in patients after tracheostomy is likely due to TIF. Ultrasound scanning before PDT and careful periodical followup of the trachea are required.