Background Celiac disease (CD) is an autoimmune disease that affects genetically predisposed individuals. The HLA-DQ2 heterodimer is present in nearly 90% of patients while HLA-DQ8 is found in the remaining 10%. Aim To study the characteristics of CD in pediatric patients in Cantabria and their first-degree relatives, with special emphasis on factors related to haplotype, serology, and forms of clinical presentation. Patients and methods Eighty-six patients with CD and 215 first-degree relatives were HLA genotyped. Clinical, laboratory, immunologic, and histological data were obtained from all patients. Results Clinical presentation was classical in 95% of the patients and mono-symptomatic in the remaining 5%. Anti-gliadin antibodies (AGA) and anti-transglutaminase antibodies (ATGA) were positive in 95% of the patients and negative in 5% (all with IgA deficiency). DQ2 was found in 71% of the patients (homozygotes or heterozygotes) and DQ8 was found in 9.5%. No heterodimers of risk were found in 22%. CD was found in six relatives (three were positive for AGA and four were positive for ATGA). Forty-nine percent of the relatives carried the DQ2 heterodimer and 15% the DQ8 heterodimer; no heterodimers of risk were found in 40%. Conclusions The most prevalent HLA found in patients with CD in the autonomous region of Cantabria was DQ2 (71%). This prevalence is clearly lower than that reported in other Spanish regions. The prevalence of CD among firstdegree relatives was similar to that found in other studies performed in Spain (2.8%). Our data support the need for systematic study of the first-degree relatives of patients with CD.