The national bibliography in the contemporary information environment becomesthe electronic national bibliography available on CD-ROM or online. Printed editions of the national bibliographies, as well as of the Croatian National Bibliography, are being slowly abandoned. The preparation of the bibliography is based on the internationally accepted standards (ISBD) and machine readable formats. Indexes to the bibliography are the additional access point to the bibliographic database, and the type of index depends on the arrangement of the bibliographic entries in the main order of bibliographic entries - the electronic national bibliographies (e-NB) reviewed in this paper use the UDC systematic order for this purpose.