We present the humoral immunological findings in 18 patients with ulcerative colitis and two with Crohn's disease. All of them had the disease for 3 months to five years. Fifteen were hispanics and five from European origin. There were ten males and ten females, and an average age of 38 years. All patients had active disease from clinical and endoscopy points of view. Thirteen patients had abnormal values in one of the immunoglobulins and normal in seven patients. IgA was increased in eleven, normal in seven and decreased in two. IgG increased in two, decreased in one and normal in seventeen cases. IgM was found to be increased in five and normal in the rest. IgA secretory determination in saliva, was performed twelve patients and was positive in all of them. Antinuclear antibodies were negative in eight. Anti-smooth muscle were positive in three of fifteen. Anti-mitochondrial were present in one and negative in thirteen. Values of C3 and C4 were lower than normal in 3 and 2 cases respectively from 4 cases studied. CH50 was decreased in 2 of 11 cases studied. In the patients, no correlation was found between low complement values, the positivity of auto antibodies and the clinical parameters previously mentioned. We conclude that there is quantitative alterations of the humoral response and it is necessary the immunological study in persons with inflammatory bowel disease others studies are needed to establish the real value of these findings.