A restriction map of a 5.1-kilobase EcoRI fragment encoding an enterococcal beta-lactamase was prepared and compared with the restriction map of a cloned staphylococcal beta-lactamase gene and with the published maps of several other staphylococcal beta-lactamase genes. Comparison and hybridization studies showed that there were identical restriction sites in the region of the bla structural gene but not in the region surrounding this gene.