An ELISA based on a pool of United States strains of Helicobacter pylori was compared with a newly developed ELISA based on a pool of Chinese strains. Both assays were tested using sera from 132 Chinese study subjects with biopsy-proven H. pylori infection. Using cutpoints designed to yield equal specificities of 94.9% in an uninfected control population, the sensitivity of the Chinese assay was 100.0%, compared to 97.7% for the United States assay (P = 0.25 by McNemar test). These results suggest that a H. pylori assay based on pooled antigens from United States strains will perform as well in the rural Chinese population as one based on antigens from Chinese strains.