Celiac disease is a permanent gluten intolerance followed by a variety of symptoms and damage to the enterocite. Forty families of celiac patients were investigated in the period of March 1992 through March 1993. The aim of the study was to utilize a dosage of serum antigliadin antibody (IgA and IgG) as screening method to stablish the frequency of celiac disease in siblings of carriers of the disease and diagnose it in first degree relatives of those patients. The 121 relatives who agreed to take part on the study were submitted to an inquire, evaluation of nutritional status and collecting 3 ml of venous blood for dosage of antigliadin antibody class IgA and IgG. Positive sorology was obtained in seven subjects and a biopsy could be obtained in five. One mother presented a pathologic anatomical picture of celiac disease representing sibling frequency of 0.8% in the group of relatives studied.