OBJECTIVES: To evaluate the gluten-free diet (GFD) adherenceafter one year of follow-up in children with screening-detected celiac disease (CD) in a general population. METHODS: A total of 18,325 12 year olds were invited to participate in apopulation-based CD screening (ETICS- Exploring the Iceberg of Celiacs in Sweden), of whom 13,279 participated. In 240 children, CD was detected through elevated anti-tissue transglutaminase antibodies 2 (TG2-IgA) and verified by a small-intestinal biopsy. This sub-study included the 210 children with TG2-IgAevaluated both at the initialbiopsy occasion and at the one-year follow-up. GFD adherence was evaluated by a combination of TG2-IgA measurements and self-reported adherence (n = 193). RESULTS: After one year, 83% (179/210) had normalizedTG2-IgA levels (<5U/mL). Among those who had >50 U/mL at diagnosis,25% (16/63) still had elevated TG2-IgA but for the majority their initial values were more than halved. Most reported a high level ofGFD adherence ('always' 75%(158/193) and 'often' 14%(30/193)), and 75% (145/193) reported always adhereingcombined with normalized TG2-IgA. Although reporting that they were always adherent, 13 (6.7%) had not yet normalized their TG2-IgA levels completely, however, a majority of these initially had the highestTG2-IgA levels. CONCLUSIONS: GFD adherence is high in adolescents with CD detected by screening of the general population of Swedish 12yearolds. Almost all had normalized serology and reported GFD adherenceat the one-year follow-up. However, a few adolescents whoreported GFD adherence still had elevated TG2-IgA levelssuggesting more severe disease and/or non-adherence.