To estimate the levels of trace elements in children with inflammatory bowel disease (IBD). Prospective cross sectional study. Gastroentrology Unit, Great Ormond Street Children's Hospital, London, UK. Seventy four children with inflammatory bowel disease confirmed endoscopically and histologically (38 ulcerative colitis and 36 Crohn's disease) and 40 age matched controls had their serum zinc, copper and selenium assayed at presentation. Serum levels of zinc, copper and selenium in children with inflammatory bowel disease and age matched controls. Seventy four children with inflammatory bowel disease confirmed endoscopically and histologically (38 ulcerative colitis and 36 Crohn's disease) and 40 age matched controls had their serum zinc, copper and selenium assayed at presentation. The serum levels of selenium were significantly lower in cases of ulcerative colitis 0.63 +/- 0.25 mmol/L and Crohn's disease 0.69 +/- 0.25 mmol/L than in the controls 0.84 +/- 0.13 mmol/L (p < 0.01). The serum copper concentration was significantly higher in those with Crohn's disease 22.7 +/- 5.49 mmol/L than in those with ulcerative colitis 17.6 +/- 5.15 mmol/L and the controls 20.76 +/- 4.06 mmol/L (p < 0.01). Children with Crohn's disease had a lower serum zinc level 11.01 +/- 2.49 mmol/L compared to the control level of 13.6 +/- 1.63 mmol/L (p < 0.05), but the levels were not significantly different in the controls and ulcerative colitis (p > 0.10). Children with inflammatory bowel disease have abnormal levels of the trace elements which is more marked in those with Crohn's disease. Children with IBD in this study show abnormalities of the trace elements which is probably a result of inadequate intake, reduced absorption, increased intestinal loss due to impairment of the absorption as a result of the inflammatory process. The reduced free radical scavenging action of zinc and selenium as a result of their deficiency may contribute to the continued inflammatory process of IBD. The recommendation of the supplementation of these trace elements in IBD is further supported by the findings of this study in children.