Increased expression of intercellular adhesion molecule‐1 (ICAM‐1) in the colon of inflammatory bowel disease (IBD) has been reported. We evaluated the effects of monoclonal antibodies to ICAM‐1 on acute colitis induced by dextran sodium sulphate (DSS) in rats. Colitis was induced by feeding rats 3% DSS for 7 days. Anti‐ICAM‐1 antibody or vehicle alone was injected intraperitoneally in rats daily from day 0 to day 6. On day 7 the rats were killed and colitis was evaluated histologically. Prophylactic treatment with anti‐ICAM‐1 significantly attenuated colonic damage, neutrophil infiltration and the shortening of the colon in DSS colitis. Our findings demonstrate that ICAM‐1 plays an important role in this model of inflammatory bowel disease. Although this study does not directly address the effect of anti‐ICAM‐1 therapy in IBD, our findings encourage experiments using therapies that target ICAM‐1 in rats with already developed disease.