Novel markers to reflect the intestinal damage in coeliac disease are needed. We studied the potential of faecal and serum neopterin, and faecal myeloperoxidase, human β-defensin-2, and lipocalin-2 in a case-control study. Data were collected from medical records and a biobank including newly diagnosed coeliac disease patients, potential coeliac disease patients and non-coeliac controls. Commercially available ELISA assays were used for measuring the biomarkers. Altogether 19 patients with coeliac disease (median age 9.0 years), 8 with potential coeliac disease (4.0 years) and 18 controls (6.5 years) were included. The highest faecal neopterin levels were seen in potential coeliac disease, followed by controls and coeliac disease (median 513 vs. 372 vs. 255 nmol/L, respectively, p = 0.016). Also, serum neopterin was highest in the potential coeliac disease group (9.8 vs. 5.5 vs. 5.9 nmol/L, p = 0.022). After age adjustment and robust variance estimation, only differences in serum neopterin remained significant. Other markers did not differ between the groups. None of the markers were significantly associated with serum transglutaminase-2 antibody levels. Differences in neopterin levels amongst patients with potential coeliac disease, coeliac disease, and controls suggest that neopterin might serve as an early disease marker.