We have made comparative examinations of grapevine cultivars based on the different resveratrol concentrations measured in the various parts of the plants. The detectable resveratrol levels in flagshoots, developed leaves, shoots and fruit tissues were determined. Comparative measurements were conducted (young and old leaves and shoots of each cultivar) to see whether the changes in resveratrol concentrations were influenced by the level of organ development and age. Stress related accumulation of resveratrol was tested in cultivars and hybrids representing different levels of disease resistance. As a part of this the effect of UV radiation (on adaxial and abaxial leaf surfaces), mechanical injury and treatment with CuSO4 was examined on young and old leaves and shoots. For the determination of the resveratrol concentration we have worked out a new OPLC (Overpressured Layer Chromatography) method.