Plant cell suspensions of different species were subjected to various levels of hydrodynamic stress generated by a Rushton impeller in a fermenter . Experiments were carried out in both batch and continuous culture. To assess the effects of hydrodynamic stress, various culture parameters were followed. Comparisons were made with growth characteristics obtained at low levels of hydrodynamic stress. The cell lines Catharanthus roseus and Nicotiana tabacum were capable of growth under conditions of high hydrodynamic stress which were similar to those in a 25-m-(3) stirred-tank production fermenter Cinchona robusta and Tabernaemontana divaricata were found to be more sensitive to hydrodynamic stress. The variation in the hydrodynamic stress sensitivity of the cells depended strongly on the cell line used and could not be explained from the experimental data. The dependence of the hydrodynamic stress sensitivity of a cell line might be governed by a combination of effects : the species investigated, the subcultivation regime, and the growth conditions.