OBJECTIVES: The aims of this study were to evaluate the following: 1) the prevalence of hypertransaminasemia (HT) in a pediatric celiac disease (CD) and its relation with clinical parameters; 2) the frequency of HT as the only manifestation of pediatric CD; and 3) the evolution of HT after a gluten free diet. METHODS: A total of 114 consecutive pediatric CD patients were studied (60% with classical and 40% with atypical forms). Antiendomisyum antibodies and anti-tissue transglutaminase antibodies were determined in patients with a clinical suspicion of CD (including unexplained chronic HT), in patients at risk, and in patients with preoperative increased ALT activity for minor surgery. CD was confirmed by duodenal biopsy. At baseline, the relationship between clinical factors and aminotransferase status was univariately and multivariately assessed. After starting a gluten free diet, patients were followed up, until serological markers cleared and serum aminotransferase normalized. RESULTS: HT occurred in 32% of patients (37 of 114) at diagnosis. HT was the only manifestation of CD in five patients (4.3%). Patients with HT were younger (2.9 ± 0.4 yr) than patients with normal aminotransferases (5.1 ± 0.5 yr) (p = 0.007). A higher percentage of patients with classical CD tend to have abnormal aminotransferases (73%; 95% CI = 65-81%) than do patients with atypical CD (27%; 95% CI = 19-35%) (p = 0.068). Logistic regression analysis showed that only younger age was significantly associated with HT (p = 0.039; OR = 0.8; 95% CI = 0.71-0.99). Aminotransferases normalized with a gluten free diet in all 35 patients who were followed-up, either before (n = 18) or at the same time (n = 17) as serological markers cleared. CONCLUSIONS: HT is a frequent finding in pediatric CD patients and, in a substantial proportion, may be the only manifestation of CD. Thus, serological markers of CD should be introduced in the first step of the diagnostic workup of liver diseases in pediatric patients. (Am J Gastroenterol 2002;97: © 2002 by Am. Coll. of Gastroenterology).