Traditional elderflower beverages are very popular due to their pleasing taste and pro-health properties. Phenolics were quantified in three elderflower extracts (methanolic extraction and two water extracts prepared as fresh drinks according to local recipes) with HPLC-MS. Chromatographic patterns of methanolic and water extracts were quite similar; however, content levels of individual compounds differed between the two extraction solvents. Two feruloylquinic acids and two p-coumaroyl-caffeoylquinic acids and different flavonol glycosides have been identified in elderflowers for the first time. Hydroxycinnamic acids and flavonol glycosides were the major phenolic constituents in elderflowers. Methanolic extract contained higher levels of all phenolic groups compared to water-extracted samples. The yield of elderflower extracts depended on extract solution and time of extraction. Elderflower beverages were characterized by high total phenolic content (91.09 to 746.63 mg GAE/L). The results confirmed that elderflower beverages (sabesa, syrup) should be recommended as a good source of phenolics in human diet.