Immortelle (Helichrysum italicum (Roth) G. Don) is an aromatic semi-shrub of Mediterranean region known for its golden-yellow flowers and easily recognizable smell. Helichrysum genus name, which comes from the Greek words helios, meaning sun, and chryos, which means gold, makes it clear how the species of this genus have a distinctive blossoms light-yellow color. In Croatia immortelle grows at a rocky, busic, cliffy lawns, from coastal to mountainous zone in the mediterranean and sub-mediterranean climate. The aim of this study was to determine the influence of the increasing concentration of saccharose in the nutrient medium on the amount of phenolic compounds (total phenols, tannins, flavonoids and anthocyanins) and antioxidant capacity of immortelle. In this study only leaves of Immortelle were used. They were extracted using 50 % ethanol. The results showed that conclusive increase of saccharose concentration in the nutrient medium, significantly increased the amount of phenolic compounds in the immortelle leaves. That could be attributed to the stimulating effect of saccharose on enzyme phenylalanine-ammonia-lyase (PAL ), a major enzyme in the synthesis of secondary phenolic metabolites in plants. ABTS, DPPH and FRAP assays were used to determine the antioxidant capacity of immortelle extracts. With increasing concentration of saccharose, and thus increasing amount of phenolic compounds in the immortelle leaves the antioxidant capacity was higher according to ABTS and FRAP assays. DPPH assay showed a decline in antioxidant activity which could be explained by the formation of hydrogen bonds between the solvent (ethanol and water) and elevated levels of phenolic compounds that have influenced on reduced rate of reaction between radicals and antioxidants (phenolic compounds) from the immortelle leaves.