Dimeric procyanidins B1 to B8 could be produced via semisynthesis from a polymeric proanthocyanidin fraction of hazelnut skins (Corylus avellana L.). This polymeric fraction was found to consist of (+)-catechin and (-)-epicatechin as upper units. Therefore, according to the choice of nucleophiles it is possible to prepare dimeric procyanidins B1, B3, B6, and B7 with (+)-catechin and B2, B4, B5, and B8 with (-)-epicatechin. The semisynthetic mixtures were separated on a preparative scale using high-speed countercurrent chromatography (HSCCC) and low-speed rotary countercurrent chromatography (LSRCCC). C4→C8 linked dimeric procyanidins B1 to B4 could be isolated in amounts of 350 to 740 mg. To the best of our knowledge this is the first study isolating dimeric procyanidins B1 to B8 in large amounts with countercurrent chromatography. Moreover, the dimeric prodelphinidins B1, B2 and B3 and their structural elucidation by 1H-NMR spectroscopy without peracetylation are described for hazelnuts as natural compounds for the first time.