The effects of a single 50 mg intramuscular injection of the anabolic steroid stanozolol (Stromba) on fibrinolysis, blood coagulation and lipids was evaluated in 12 healthy male volunteers. Significantly increased plasminogen activator levels (p less than 0.05) was noted 24 hours following the injection and these remained elevated for one week. Plasminogen levels increased significantly by day two (p less than 0.01) and remained elevated for three weeks. HDL cholesterol fell (p less than 0.01) and both total and LDL cholesterol increased (p less than 0.05) when measured one month post injection. Stanozolol appears to have therapeutic potential as an activator of the fibrinolytic system when given by intramuscular injection.