Anti-Saccharomyces cerevisiae antibodies (ASCA) are found in 50-60% of patients with Crohn's disease. Increased as well as normal levels have been reported in Behçet's syndrome (BS). We reassessed the level of IgG and IgA ASCA antibodies in BS and in a group of diseased and healthy controls.Eighty-five patients with BS were studied along with 20 patients with ankylosing spondylitis (AS), 24 with Crohn's disease (CD), 25 with ulcerative colitis (UC) and 21 healthy volunteers. A commercial ELISA kit was used (Inova Diagnostics).It was only the patients with CD who had significantly higher levels of antibodies compared with the rest of the group (ANOVA: ASCA IgG, p = 0.0001; ASCA IgA, p = 0.0001). 42% of CD, 4% of BS, 4% of UC and 15% of AS patients had a positive IgG+IgA ASCA. There was a significant trend for patients with gastrointestinal (GI) involvement with BS (n = 8) to be more positive for IgG and IgG+IgA ASCA compared to the rest of the patients with BS (n = 77) (Chi-square, IgG, p = 0.02, IgG+IgA, p = 0.001).The rate of positivity of ASCA in BS is comparable to that observed among patients with UC and AS. Patients with BS who have GI involvement may have higher levels of ASCA and this needs to be further studied.