Luminal prostheses comprise scaffolds having coatings adhered to at least a portion of their outer surfaces. The surfaces are modified to enhance binding of the coatings. For example, the surfaces may be microblasted, laser treated, chemically etched, exposed to plasma, or exposed to a corona discharge, allowing a polymeric coating to adhere to the scaffold more tightly than in the absence of the surface modification. The coatings can be used to deliver therapeutic or other agents dispersed therein.