The regulations to phase out stall and tether systems by 1 January 1999 will result in UK sows being group housed. The formation of either small stable groups or large, dynamic groups by mixing unfamiliar sows results in aggression between sows. One consequence of aggression is damage to the skin which, if severe may compromise the welfare of the sow. To assess the level of damage resulting from aggression between sows, a simple, rapid scoring method is needed. The objective of this work was to establish which areas of the sow were the main target sites for attack and to use this information to devise an animal based method of scoring damage.