Serology, 13C-urea breath test, histology, Campylobacter-like organism testing, and culture were performed in 95 consecutive children to evaluate the contribution of these tests to the detection of Helicobacter pylori infection. In analyses considering any combination of three positive tests as "gold standard" for diagnosing H pylori infection, 26 children were Helicobacter positive (27%), which is only one patient more than the number of children with only a positive culture. The accuracy of culture was excellent when "any combination of three positive tests" was used as the gold standard (sensitivity 96%, specificity 100%, positive predictive value 100% [false positivity 0%], negative predictive value 99% [false-negative results 1%]). The results of invasive and noninvasive tests were comparable. When culture was considered as "gold standard," the sensitivity of serology and 13C-urea breath test was 96%; the specificity was 96% and 93%, respectively; the positive predictive value was 89% and 83% (false-positive results in 11% and 17%); and the negative predictive value for both was 99% (false-negative results in 1%). It is concluded that culture can be used as gold standard, but that non-invasive tests such as serology and/or 13C-urea breath test can be used to diagnose H pylori infection in children, since each has at least 95% sensitivity and 92% specificity.