Novel compounds having activity as non-covalent inhibitors of urokinase and having activity in reducing or inhibiting blood vessel formation are provided. These compounds have at a group having a guanidino moiety or derivative thereof. These compounds are useful in vitro for monitoring plasminogen activator levels and in vivo in treatment of conditions which are ameliorated by inhibition of or decreased activity of urokinase and in treating pathologic conditions wherein blood vessel formation is related to a pathologic condition.