Plant genetic resources are the most important source for forming the biological fundamentals of agriculture and the plant’s potential for nature. The Bulgarian genebank as a part of the IPGR-Sadovo is a specialized facility whose main activity is to conserve plant biodiversity in a living state by applying ex situ short-term, medium-term, and long-term seed conservation methods. A total of 53,997 accessions have been maintained since its establishment in 1984, of which 44,850 accessions with different geographic origins form the base collection. It is composed of 35 families, 158 genera, and 550 plant species. This chapter aims to present the activity of ex situ genebank conservation based on 40 years of experience. The genebank activity is discussed chronologically regarding the steps of development of the Bulgarian plant genetic resources program. The organizational structure and genebank operation are described. The status of the collection is discussed by crop group and by taxonomic description. References are provided from the annual reports of the genebank for the period 2000–2022 related to the enrichment of collections with new germplasm, the number of accessions evaluated by descriptors and included in comparative variety trials, and the number of reproduced accessions. The utilization of PGR is illustrated by data for sample exchange. Various aspects of the use of PGR are also discussed. Based on the specific approaches for long-term seed storage, precautions and priorities for sustainable germplasm storage and use in view of changing climatic conditions are outlined.