The main polyphenols in callus and cell suspension cultures of Taxus cuspidata and T. baccata were (+)-catechin and (-)-epicatechin, while lignans, such as (+)-taxiresinol, (+)-isotaxiresinol, (+)-isolariciresinol and (-)-secoisolariciresinol, were present in trace amounts. T. cuspidata cells contained 1.7% (+)-catechin and 2.4% (-)-epicatechin on dry wt basis but when stimulated with methyl jasmonate produced 3.4% catechin and 5.2% epicatechin. These are the highest levels of these metabolites obtained in plant cell cultures.