The aim of this study was to evaluate the performance of three antigenic preparations for serological diagnosis of Helicobacter pylori infection: (i) native antigens from Helicobacter pylori strain N6 or its aflagellated isogenic mutant N6flbA-, or an acellular extract (antigen AgFA) from a pool of six clinical strains; (ii) recombinant antigens consisting of CagA fused to MS2 polymerase and HspA or recombinant UreA and UreB fused to the maltose-binding protein, and (iii) the preparations provided with two commercial kits, the Cobas Core (Roche Diagnostic Systems, France) and the Pylori Stat (BioWhittaker, Belgium). All preparations were used in an enzyme immunoassay to test 92 sera from dyspeptic patients for whom the status of Helicobacter infection was established. Sensitivities were higher (90 to 100%) for the native antigens and the commercial kits than for the recombinant antigens. Specificities were higher than 90%, except with UreA + UreB (42%). The most useful antigens were those extracted from strains N6 and N6flbA-.