Wound contamination and the resultant postoperative infection is a major problem in all forms of surgery. Air contamination, gloves, surgical instruments and drapes have all been investigated as sources of wound contamination. We investigated the effect of different wetting agents on strike-through rate of bacteria through re-usable polyester/cotton surgical drapes using a newly described method. Within 30 min bacterial strike-through of dry surgical drapes occurs. Wetting drapes with blood or normal saline enhances the strike-through rate of bacteria. Wetting drapes with iodine or chlorhexidine diminishes, but does not stop, bacterial strike-through. The use of re-usable polyester/cotton drapes is a potential source of wound contamination especially when wetted with blood or normal saline.