Polymer fibers are used for a wide range of materials in contact with the human body Since bacterial contamination may cause diseases, it is desirable to provide fibers with antimicrobial properties This work investigates the ability of silver-tricalcium phosphate nanoparticles (Ag/TCP) to build a reactive system when incorporated in polyamide fibers In the presence of bacteria, the TCP carrier particles are biodegraded and trigger the release of silver For this work, Ag/TCP nanoparticles (1 3 wt% silver) were produced by flame spray synthesis and subsequently processed with polyamide 6 to fibers (125-mu m thick, containing 260 pm silver) with the aid of extrusion and melt-spinning for subsequent antibacterial testing The fibers were contaminated with the clinically relevant strains Escherichia coli or Streptococcus sanguinis, respectively The reactive fibers demonstrated significantly reduced plate count within 24 h (the number of colony forming units was reduced by 99 999% with E coli and 99 6% with S sanguinis compared with pure PA6 reference fibers) These reactive properties of easily integrated antibacterial silver suggest an implementation of intelligent fibers to a wide range of applications POLYM ENG SCI, 51 71-77, 2011 (C) 2010 Society of Plastics Engineers