Serum levels of zinc, copper, and selenium, and alkaline phosphatase activity were prospectively studied in 29 patients with inflammatory bowel disease. Fifteen patients had extensive active colitis (active colitis group). Seven patients had active, and seven cases inactive small bowel or ileocecal Crohn's disease (small bowel disease group). Ninety-three healthy subjects acted as controls. Serum trace element levels were considered in relation to vitamin A and E levels, nutritional parameters, the activity of the disease, and the recent intake of steroids. The effect of total enteral nutrition on serum trace elements was studied in seven cases. Serum zinc levels were lower and serum copper levels higher in the active colitis group than in controls (p = 0.0007, and p = 0.02, respectively). More than 50% of patients with active colonic or small bowel disease showed zinc levels below the 15th percentile of the control group. Serum zinc levels correlated with plasma vitamin A in acute colitis (r = 0.67; p = 0.006), and with both serum albumin concentration (r = 0.76; p = 0.002) and disease activity score (r = -0.67, p = 0.009) in patients with small bowel disease. The copper:zinc ratio was higher in the active colitis group than in controls (p = 0.002). In spite of the increase in serum albumin levels and the decrease in disease activity, serum zinc levels remained low after total enteral nutrition. The implications of the abnormal trace element status in patients with inflammatory bowel disease are discussed.