Regulatory CD4 + CD25 + Foxp3 + T cells are involved in the regulation of immune response and inhibit protective antitumor immunity. Celiac disease (CD), a food gluten–sensitive enteropathy, is considered a T-cell–mediated autoimmune disease and is generally associated with an overall increased risk of cancer in CD patients. We observed a higher percentage of circulating CD4 + CD25 + Foxp3 + T cells and an increased Foxp3 expression in CD4 + CD25 + T cells from untreated than from treated CD patients. In co-culture, CD4 + CD25 + T cells from both treated and untreated CD patients significantly suppressed the proliferation of autologous CD4 + CD25 − T cells similarly to values in healthy subjects. Our study suggests that Treg proportion and Foxp3 expression in circulating CD4 + CD25 + T cells could justify the increased global risk of malignancy in CD population and support the efficacy of lifelong gluten-free diet in the reduction of the cancer risk.