The effect of dry powder povidone-iodine (Disadine D.P.) on wound healing was assessed experimentally and clinically. It did not interfere with wound healing macroscopically, histologically or mechanically in Wistar rats. One hundred and one patients undergoing 'clean' elective surgery were included in the controlled clinical study and povidone-iodine did not affect wound healing in any way. In the control group 4% of patients developed infection compared with none of those sprayed with povidone-iodine. No adverse reaction to povidone-iodine was seen in either study. This antiseptic offers a safe alternative to antibiotics for use at operation whenever there is risk of wound infection from operative bacterial contamination.