St. John’s wort (Hypericum perforatum L.) is the most important species of the genus Hypericum and produces a wide range of chemical constituents including essential oil. Regarding advantages of in vitro culture techniques in production of desired metabolites, the present study was aimed to investigate volatile constituents of H. perforatum shoots cultured in different basal media. Shoot cultures were established by culturing six nodes of aseptic plants in three liquid media including MS (Murashige and Skoog), B5 (Gamborg B-5) and half-strength B5 containing 30 g L-1 sucrose and 0.5 mg L-1 BA (6-benzyladenine). According to the results, growth and profile of volatile constituents of cultured shoots were affected by the type of medium used and shoots cultured in the B5 medium exhibited the highest growth which was reached to 42.95 g flask-1. On the other hand, 44 components were totally identified by GC-FID and GCMS analysis of essential oils of cultured shoots. Decane (27.7%), menthol (8.9%), methyl decanoate (4.6%) and β-elemene (4.6%) were the major volatile constituents of the shoots cultured in MS medium, while eudesma4(15),7-dien-1-β-ol (8.1-7.5%), thymol (7-7.2%) and 1,4-trans-1,7-trans-acorenone (5.2-5.5%) were found as the principal components of shoots cultured in B5 and half-strength B5 media
