Novel methods for, inhibiting angiogenesis and treating diseases associatedwith angiogenesis are described. The methods may comprise administering to apatient an effective amount of a 1,2-dithiol-3-thione derivative 'Ormetabolite thereof. Preferred compounds for use in the methods include 5-(2-pyrazinyl)-4methyl-1, 2-dithiol-3-thione (Oltipraz) and its metabolites.