Serum concentrations of bilirubin, albumin, and uric acid (UA) play important roles in controlling oxidative stress. Until now, there are few researches related to the relationship between oxidative stress and Crohn's disease (CD); furthermore, no such study has been reported from China. Our aim was to evaluate serum bilirubin, albumin, and UA levels in CD patients and relate them to disease activity.Seventy-one patients diagnosed with CD and 125 sex- and age-matched healthy individuals were retrospectively analyzed during the same period. Clinical characteristics and laboratory parameters were analyzed in CD patients and healthy control groups.Serum levels of bilirubin, albumin, and UA in patients with CD were significantly lower than those in the healthy control group. Correlation analysis demonstrated that serum concentrations of total bilirubin, direct bilirubin, indirect bilirubin, albumin, and UA were negatively related to disease activity in patients with CD (r = -0.620, P < .001; r = -0.304, P < .05; r = -0.623, P < .001; r = -0.408, P < .01; and r = -0.296, P < .05; respectively).Serum bilirubin, albumin and UA levels were significantly lower in CD patients, suggesting potential correlations between serum bilirubin, albumin, and UA levels and disease activity in CD patients. In addition, the noninvasive biochemical index may be potential markers for assessing the disease activity of patients with CD.