The relationship between anti-neutrophil cytoplasmic auto-antibodies (ANCA) and disease activity in inflammatory bowel diseases remains controversial. The aim of this study was to highlight the relationship between ANCA presence or titers and disease activity in ulcerative colitis (UC). Three groups of patients with UC were studied: 1) group A included 39 patients who had not undergone colectomy, 2) group B, 43 patients with subtotal colectomy and ileo-rectal anastomosis, 3) group C, 98 patients with proctocolectomy and ileo-anal anastomosis, including 88% with pouchitis and 12% without pouchitis at the time of the study. Determination of ANCA was performed using the standardized indirect immunofluorescence assay. ANCA were positive in 59%, 65%, and 54% of patients from groups A, B, and C, respectively (NS). No relationship between ANCA presence or titers and UC activity could be detected within groups A and B. In group C, 45 of 86 patients (52%) without pouchitis and 8 of 12 patients (67%) with pouchitis, were ANCA positive (NS). These results do not support a relationship between ANCA and UC activity in this cohort of 180 patients.