In a retrospective, non-randomised, controlled longitudinal cohort study the preventive effect of different wound irrigation solutions on wound infection was investigated: Polyhexanide (PHMB), PVP iodine, hydrogen peroxide and Ringer's solution. Overall 4.2% of patients developed an SSI. The lowest percentage of SSIs occurred in the treatment group with wounds irrigated with PHMB (61 of 3,264 patients, 1.9 %), the most in wounds irrigated with hydrogen peroxide (75 of 643 patients, 11.7 %).