This study was carried out first to determine if virus concentration by adsorption to glass wool was suitable for the detection of enterovirus genomes by seminested RT-PCR in treated wastewater, and second to compare the presence of infectious enteroviruses and enterovirus genomes. The experiments were performed on 57 treated wastewater samples from two wastewater treatment plants which use different processes. The water samples were analysed directly and after concentration on glass wool. Concerning the effect of a concentration step on glass wool, the results show that after concentration, the number of positive samples increases significantly for both infectious enteroviruses (17 vs 0) and enterovirus genomes (37 vs 9). Concerning the comparison of the presence of infectious enteroviruses and enterovirus genomes, it appears for all the samples analysed that the number of positive samples for enterovirus genomes is significantly higher than those for infectious enteroviruses (37 vs 17). Therefore, the presence of enterovirus genomes cannot be considered to be an indicator of the presence of infectious enteroviruses, strictly speaking, but only an indicator of more or less recent viral contamination. However, 3 samples containing infectious enteroviruses are negative by seminested RT-PCR. These false negative results can be explained by the presence of substances that inhibit seminested RT-PCR reactions.