Thrombolytic drugs activate plasminogen which creates a cleaved form called plasmin, a proteolytic enzyme that breaks the crosslinks between fibrin molecules. The crosslinks create blood clots, so reteplase dissolves blood clots. Tissue plasminogen activator (tPA) is a well-known thrombolytic drug and is fibrin specific. Reteplase is a modified nonglycosylated recombinant form of tPA used to dissolve intracoronary emboli, lysis of acute pulmonary emboli, and handling of myocardial infarction. This protein contains kringle-2 and serine protease domains. The lack of glycosylation means that a prokaryotic system can be used to express reteplase. Therefore, the production of reteplase is more affordable than that of tPA. Different methods have been proposed to improve the production of reteplase. This article reviews the structure and function of reteplase as well as the methods used to produce it.