Celiac disease (CD) is strongly related to human leukocyte antigens (HLA) genes. The incidence of CD is very low in patients without the HLA-DQ2.5 and HLA-DQ8 leukocyte antigens. This study presents two families with CD and shows that the disease might be familial. The determination of HLA tissue groups is important and family screening tests may lead to early diagnose of the disease. In both of the families, the patients' siblings and fathers were asymptomatic, but diagnoses were made after family screening tests. HLA tissue typing was performed in all family members. The patients, siblings and fathers carried the HLADR3-DQA1*0501-DQB1*0201 tissue groups in both two families while this tissue group was not present in the mothers. As CD is strongly related to certain HLA groups and has a genetic predisposition, all members of a family must be screened when a case of CD is diagnosed in any family member. On the other hand, the determination of the HLA tissue type in patients with both symptoms and very positive serologic tests is important in terms of suspicion of the disease.