Background. Celiac disease (CD) is significantly underdiagnosed, despite significant efforts made in the last decades to increase its diagnostic rate. This has lead to a high need for developing new diagnostic strategies. Our aim was to evaluate the diagnostic performance of two routine hematologic indices for CD. Methods. In a prospective observational study, 34 newly diagnosed CD patients, 34 age-sex matched controls with irritable bowel syndrome (IBS) and 16 treated CD patients were assessed regarding the differences in mean lymphocyte count (LY), red blood cell distribution width (RDW) and their ratio (RDW/LY). Results. Elevated RDW (>14) and lymphopenia (<1.5 x 10e9/L) were more frequently seen in newly diagnosed CD patients compared to IBS control group and treated CD patients. Newly diagnosed CD patients had significantly higher mean values of RDW/LY - 10.09, compared to 7.72 in the CD-treated group and 6.79 in IBS controls (p<0.01). Subgroup analysis revealed that RDW/LY was higher in patients with destructive histology (Marsh≥3a), 10.54 vs. 7.99. For a value over 7, RDW/LY had a sensitivity of 88.24% (95% CI 72.55-96.70%) and AUROC of 0.785 (95% CI 0.683- 0.887). Conclusions. RDW/LY ratio is a widely available tool which could be used routinely in clinical practice for CD screening.