Abstract: Surface-active, non-leaching antimicrobial film forming compositions and methods for their application to preferably medical device surfaces are provided. The compositions form durable coatings with long-lasting antimicrobial efficacy without formation of a zone of inhibition. Optionally the films can be hydrophilic. Specific long-chain molecules of certain chemical reactivity are covalently bonded into a polymeric matrix. They maintain a long-term anti-microbial efficacy without being leached out into the aqueous environment. The polymeric matrix of the compositions contain functional groups, which covalently bond to an amine, thiol, carboxyl, aldehyde or hydroxyl active group of selected long chain quaternary ammonium compounds. Upon formation of a covalent bonding with the polymeric matrix the long chain compounds become immobilized but still maintain antimicrobial efficacy.