The article describes cataloguing monographic publications on CD-ROM, which is currently the most frequently used media for storing locally accessed electronic resources in Croatian libraries. It describes technical characteristics of a CD-ROM, which dictate the choice of the processing method, and analyses the methods of description. Several examples of publications issued in their CD-ROM version are given. CD-ROMs are catalogued according to the ISBD(ER), international standard bibliographic description for electronic resources. When a CD-ROM publication carries the characteristics described by other ISBD standards, the standards for a particular type of resources should be applied too. Since monographic CD-ROM publications are issued as individual bibliographic units or as supplements to printed publications, the bibliographic entries should also match the issuing method.