Polypropylene (PP) sutures are prepared by the simultaneous radiation grafting of 1-vinylimidazole (VIm) onto PP monofilament sutures. The tenacity slightly decreases whereas the elongation increases with the increase in the degree of grafting. Thermogravimetric analysis shows that the stability of the sutures is enhanced by the grafting process. The grafted sutures have reasonably good water uptake. They are subsequently immobilized with an antimicrobial drug, ciprofloxacin. The modified suture releases the drug over a period of 4-5 days. The antimicrobial activity of the modified suture is determined against Esherichia coli by the zone of inhibition technique. A clear zone of inhibition is observed around the drug-containing suture. (c) 2006 Wiley Periodicals, Inc.