In the age of on-line catalogues an urgent need emered for the searchability of the complete collections gedfor the bility of libraries. These needs were reinforced by retrospective conversions. Since retroconversion is a time consuming and labour intensive task, outside support is required to its performance. Having considered Hungarian needs, the National Széchényi Library (NSZL) prepared two proposals, upon ministerial request, regarding this issue in 1993 and 1994 respectively: Organisational problems of the complitation of the retrospective national bibliography were emphasised. Estimated costs were unacceptable, and no steps were made for the attainment of the goals. The NSZL has two tasks ahead: publications belonging to the system of the national bibliography have to be converted, and it must be decided whether a computerised retrospective national bibliography or a computerised retrospective on-line catalogue is to be prepared. The optimal solution would be the extension of the retrospective on- line catalogue of the NSZL, that also made the generation of an on-line bibliography possible. Meanwhile the NSZL plans a transition from DOBIS/LIBIS to AMICUS, that required the conversion of the existing databases of the NSZL. The author makes detailed proposals for the achievement of complete retroconversion. She made plans for books, however; other types of material should also be included. The tasks would be managed by a temporary retroconversion unit, while the staff of the NSZL. would be responsible for intellectual duties. Continuous financial support of the Ministry is indispensable.