The use of intravenous thrombolytic agents has revolutionised the treatment of acute myocardial infarction. However, the improved mortality achieved with these drugs is tempered by the risk of serious bleeding complications, especially intracranial haemorrhage (ICH). Tenecteplase (TNKase, Genetech Inc.) is an engineered variant of alteplase (Activase, Genentech Inc.) designed to have increased fibrin specificity, greater efficacy and a longer half-life. The longer half-life of tenecteplase compared to alteplase allows for convenient single bolus administration of the drug. In addition, tenecteplase dosing is based on actual or estimated patient weight, which enhances both the safety and efficacy outcomes. Large clinical trials have demonstrated equivalence in mortality and ICH between tenecteplase and alteplase. Compared to alteplase, tenecteplase use leads to lower rates of bleeding complications and a decreased risk of ICH among low weight, elderly women.