The present paper provides an account of the basic technuques employed in the investigation of the grape seeds proanthocyanidins (condensed tannins). The importance and biological activity properties of these compounds are considered briefly in the introductory part, while isolation and structural investigation of grape seeds proanthocyanidins represent the basic part of the review. The references cover mostly the recent publications related to implementation of modern techniques of investigation, like high performance liquid chromatography (HPLC) and mass spectrometry (MS).