An increase in gastric intraepithelial lymphocytes has been observed in some patients with the typical small intestinal changes of celiac disease. To date, no clinical parameters have been described that identify the subset of patients more likely to have gastric involvement. In this study we compared the clinical features of celiac disease patients with and without lymphocytic gastritis to determine if the presence of gastric involvement at diagnosis portends a more severe form of celiac disease. We reviewed the pathology reports and hematoxylin and eosin-stained slides of 304 patients with biopsy-proven celiac disease diagnosed over an 11-year period. Thirty-nine of these patients had lymphocytic gastritis. Compared to patients without gastric involvement, those with lymphocytic gastritis were statistically more likely to be diagnosed at an earlier age and present with more profound laboratory findings and duodenal mucosal damage compared to patients with celiac disease without gastric involvement. These findings indicate that in the pediatric population, the presence of lymphocytic gastritis in celiac disease defines a unique group of patients with more severe disease (by clinical and laboratory measures) at the time of diagnosis.