The present disclosure relates to antimicrobial polymers which impart prolonged antimicrobial activity to a surface or in a solution, the polymers comprising as repeating monomers a polymerizable cyclic moiety forming part of the polymer backbone and an anti-microbial moiety such as a quaternary ammonium moiety in the side chain. The polymer may further comprise polymerizable units of at least one unsaturated monomer having an ethylenically unsaturated double or triple bond.