The main objective of STEMI treatment is myocardial reperfusion, although FT is a viable and efficient option, it has possible complications like any other medication. The objective of this article to analyze the complications of the pre-hospital use of Tenecteplase for the treatment of Acute Myocardial Infarction. Was performed a study cross-sectional study, carried out in the Mobile Emergency Care Services and Emergency Care Units, with data analyzed by descriptive and inferential statistics. Fifty-three (53) medical records of patients with acute myocardial infarction who used Tenecteplase were analyzed. The use of the medication within 3 hours after the onset of symptoms decreased mortality and provided clinical improvement. Outcomes without clinical improvement were associated with time to onset of use greater than 3 hours. Tenecteplase was an effective therapy when administered within the first 3 hours from the onset of symptoms. However, it was evidenced that hemorrhagic risks are possible, but depended on the dose of fibrinolytic administered, the pharmacological therapy used and the clinical condition of the population studied.