This study was undertaken to identify side-effects of high pressure irrigation. Standardized surgical wounds made in Yorkshire pigs were subjected to high pressure syringe and pulsatile irrigation. As a result of these treatments, fluids were disseminated into the adjacent tissue of the wound, predominantly in a lateral direction. Bacteria did not accompany this disseminated fluid and apparently were filtered out by the surface tissues. This treatment results in a tissue injury which impairs its defenses, making the wound more susceptible to infection. However, the remarkable cleansing capacity of high pressure irrigation appears to outweigh this side-effect, since heavily contaminated wounds subjected to this treatment heal per primum without infection.