Methods and manufacturing conditions were developed for giving ion-exchange properties to PCA fibres by graft polymerization of methacrylic acid to PCA fibres and styrene to PP fibres followed by sulfurization of the graft polystyrene. Antimicrobial surgical suture materials with fixation of antibiotics on the modified sutures by the ion-exchange mechanism were obtained. It was found that the duration and effectiveness of the antimicrobial action of the sutures are determined by the amount of antibiotic sorbed and the ionic bond strength of the latter with the ion-exchange groups in the sutures. The effect of the conditions of modification and methods of sterilization on the physicomechanical properties of the sutures was investigated. Antimicrobial surgical PCA sutures with the gentamycin Caprogent are recommended for use in general clinical practice and are being manufactured.One of the most effective methods of obtaining antimicrobial surgical suture materials is chemical modification of fibres with drugs [1]. Selection of this method predetermines a number of special requirements which must be considered in working with the initial materials and reagents.The fibres used must not only be biologically inert and sufficiently strong, but also contain active functional groups which can react with the drugs either directly or after additional modification [2]. In turn, the drugs must not be inactivated as a result of chemical addition itself or under the effect of the modification conditions. In consideration of these requirements, polycaproamide (PCA) and polypropylene (PP) fibres were used for production of antimicrobial suture materials.In view of the important losses (waste by oxidation) that take place in textile processing of fibres, chemical modification was conducted on finished textile articles. For this purpose, we made PCA and PP twisted surgical sutures with arbitrary numbers from 5/0 to 5 (metric size 1-7).To give the PCA and PP fibres antimicrobial activity, the drugs were attached to them by the ion-exchange mechanism. We developed methods for preliminary incorporation of cation-exchange groups in the fibres by grafting methacrylic acid (MAA) to the PCA fibres and styrene to PP fibres, followed by sulfonation of the graft polystyrene (PS).The reaction of grafting MAA to PCA fibre was initiated by peroxide and hydroperoxide groups obtained by mild oxidation with the Fe 3+ H 2 O 2 system. The advantages of this method are the important decrease in the probability of formation of homopolymer and preservation of the physicomechanical properties of the fibres.To incorporate peroxide and hydroperoxide groups in PCA, the fibre was successively treated with a solution of iron chloride in dilute hydrochloric acid and an aqueous solution of hydrogen peroxide. The oxidation process was monitored by the content of active oxygen in the PCA fibre.It was found that the acid medium causes swelling of PCA so that the number of peroxide and hydroperoxide groups, probably formed due to deeper penetration of the reagen...