BACKGROUND: Maintaining a gluten-free diet (GFD) without an underlying diagnosis of celiac disease has enjoyed widespread acceptance in the Unites States. METHODS: We performed a cross-sectional study using a GFD questionnaire in 1647 patients with inflammatory bowel diseases (IBD) participating in the CCFA Partners longitudinal Internet-based cohort. RESULTS: A diagnosis of celiac disease and non-celiac gluten sensitivity were reported by 10 (0.6%) and 81 (4.9%) respondents, respectively. Three hundred fourteen (19.1%) participants reported having previously tried a GFD and 135 (8.2%) reported current use of GFD. Overall 65.6% of all patients, who attempted a GFD, described an improvement of their gastrointestinal symptoms and 38.3% reported fewer or less severe IBD flares. In patients currently attempting a GFD, excellent adherence was associated with significant improvement of fatigue (P < 0.03). CONCLUSIONS: In this large group of patients with IBD, a substantial number had attempted a GFD, of whom the majority had some form of improvement in gastrointestinal symptoms. Testing a GFD in clinical practice in patients with significant intestinal symptoms, which are not solely explained by the degree of intestinal inflammation, has the potential to be a safe and highly efficient therapeutic approach. Further prospective studies into mechanisms of gluten sensitivity in IBD are warranted.