Plant cell cultures in vitro produce secondary metabolites with varied effectiveness. Despite industrial application of only few cell suspension cultures, considerable progress in research on plant cell biotechnology has been made over the last few years. Transformed organ cultures, especially hairy roots, seem to be an interesting model for stable production of plant metabolites with high yield. In this paper, cultures of hairy roots of Salvia sclarea, S. officinalis, S. miltiorrhiza, S. przewalski, and Centaurium erythracea, as well as transformed shoots and plants of C. erythracea are presented. Also, production of secondary metabolites in these cultures is discussed.