Elicitation-produced stress activates the defensive reactions of the plant or plant explant, which result, among others, in a change in the transcription of the genes coding the enzymes influencing biosynthesis of secondary metabolites. The present paper investigated the effect of ions of heavy metals in concentrations od 1; 10, and 100 microM on the production of anthracene derivatives by the explant culture of Rheum palmatum L. cultivated on Murashige-Skoog medium with an addition of 10 mg.l(-1) of alpha-naphthylacetic acid. The periods of application of elicitation were 6; 24; 48, and 168 hours. It follows from the results that the applied abiotic elicitation positively influenced the production mainly in suspension culture. The maximal increase in the content of anthracene derivatives versus the control by 66% was observed after 48-hour action of 10 microM concentration of cadmium chloride. Aluminium chloride produced the largest increase in the production after 6-hour application of a 100 microM concentration, when in comparison with the control culture the production was stimulated by 60%.