The most biologically active component of vitamin E, alpha-tocopherol, is synthesized in its most effective stereoisomeric form only by photosynthetic organisms. Using sunflower cell cultures, a suitable in vitro production system of natural alpha-tocopherol was established. The most efficient medium was found to be MS basal medium with naphthaleneacetic acid and 6-benzylaminopurine with the addition of casaminoacids and myo-inositol. Culture feeding experiments using biosynthetic precursors showed that alpha-tocopherol production improved by 30% when homogentisic acid was used. Interestingly, time-course experiments with sunflower suspension cultures showed a possible increase of 78% in alpha-tocopherol production when using cultures of longer subculture intervals. Compared to the starting plant tissue, an overall 100% increase of alpha-tocopherol was reached by these sunflower cell cultures.