Monoterpenes are considered to be one of the major classes of volatile flavour components in many grapevine cultivars and are typical of fruity and floral white wines. Varietal character largely depends on the kind and amounts of monoterpenes. GC-MS analysis showed great differences among many cultivars and clones. They are significantly influenced by environment and ripening stage, which makes a systematic clone evaluation based on phenotype difficult. The objective of this study was to identify genes involved in metabolic pathways leading to characteristic monoterpenes. The biosynthesis and molecular genetic of monoterpenes have been widely studied in various species. The recently published genome of grapevine and sequences from several other plant species, now available in databases, enable us to identify potential terpensynthases in grapevine. In this study, previously unknown putative linalool - and geraniolsynthases of grapevine were identified. One gene showed great differences between aromatic and non-aromatic cultivars. These differences will be assessed for the development of markers to use in marker-assisted breeding and marker-assisted clone selection (MACS).