The objective of this study was to assess the increasing number of patients with positive biopsies yet negative serology at Medway Hospital, Kent, through a retrospective data collection. All coeliac serology undertaken between 2003-5 (n=3056) with coeliac positive duodenal biopsy results (n=26) were compared. From the total number of patients with positive duodenal biopsies 10 (38.5%), 13 (50%) and 12 (46.2%) had negative anti-tTg, IgA anti-gliadin and IgG anti-gliadin serology respectively. When combining anti-tTG, IgG and IgA anti-gliadin to improve sensitivity, five patients (19.2%) had completely negative and six (23%) had equivocal serology results. This study shows that a small but significant number of cases of coeliac disease will be missed by relying on serology alone. As the diagnosis and management of disease shifts further towards general physicians and primary care, it is important that the limitations of serological testing are recognised.