Hypericum perforatum L. is an important ornamental species but it is also a medicinal plant because of its bioactive compounds. The effect of plant growth regulators on tissue differentiation was studied. Also the contents of the major bioactive compounds in in vitro cultures were analysed. Largest number of adventitious shoots was formed from apical shoot segments in presence of 0.5 mg l^-1 BA. Rooting of the adventitious shoots was 97% on a half-strength plant growth regulator free MS medium. 2,4-D was needed for callus induction, but it had adverse effects on tissue differentiation. Cultures with divergent differentiation levels (i.e. shoot cultures, callus cultures with adventitious buds, compact callus cultures with low level of tissue differentiation and undifferentiated callus cultures) were grown on solid media, in Erlenmeyer flasks and in bioreactors. The chemical analyses indicated that the concentrations of hypericins, pseudohypericins and phloroglucinols (more precisely, hyperforin and adhyperforin) increased with tissue differentiation. The cultures grown in liquid medium had less bioactive compounds than corresponding cultures that were grown on solid medium. However, multiplicating shoot cultures were able to accumulate high concentrations of bioactive compounds both on solid media and in bubble column bioreactors. Thus, actively multiplying shoot cultures in bubble column bioreactors with high and fast shoot-production capacities provide an attractive alternative in plant production for both ornamental and medicinal purposes.