Lebanon's well-documented history in grape cultivation and winemaking dates back millennia, intertwining with its cultural heritage and landscape. However, Lebanon's grapevine genetic resources have received limited attention until recent years. This study presents a comprehensive exploration and characterization of Lebanese local underexploited resources, beginning with the collection of 276 accessions prospected throughout the country, with an emphasis on old/abandoned vines and vineyards. Molecular and morphological analyses were conducted on these accessions: a total of 22 nuclear simple sequence repeat (SSR) markers and 3 chloroplastic SSR markers were employed to assess their genetic diversity. The results revealed 102 distinct genotypes, with 63 genotypes exhibiting original genetic signatures previously undocumented in international databases, highlighting the unique genetic richness of Lebanon's grapevine germplasm. Subsequent morphological characterization using a set of OIV descriptors provided valuable insights into the phenotypic traits of these newly found grape varieties. Parentage analysis facilitated the elucidation of genetic relationships among the accessions, and the construction of genetic pedigrees. Comparative analysis positioned Lebanese accessions within the Eastern Mediterranean group, suggesting shared genetic affinities with regional counterparts. This comprehensive study underscores the importance of Lebanon's grapevine genetic resources for conservation, breeding, and future research endeavors in viticulture. The conservation and sustainable utilization of these genetic resources is not only for preserving the nation's viticultural heritage but also for fostering vinification innovation and resilience in the face of changing environmental conditions.