The 74 samples of six HYPERICUM species (H. PERFOROTUM, H. HIRSUTUM, H. MACULATUM, H. TETRAPTERUM, H. MONTANUM, AND H. HUMIFUSUM) were collected around Slovenia and analysed for the content of ten substances (rutin, hyperoside, isoquercetin, quercitrin, quercetin, I3,II8-biapigenin, amentoflavone, pseudohypericin, hypericin, and hyperforin). The flowers were analysed separately from the green parts of the plants (herbs). The highest content of most of the substances was found in the flowers of H. PERFOROTUM. Among the herbal samples (without flowers), H. MONTANUM and H. HIRSUTUM contained significantly higher levels of amentoflavone (average 3-fold and 2.5-fold higher, respectively), than the herbs of H. PERFOROTUM. In the herbal part of H. PERFOROTUM the contents of all constituents strongly correlate with the contents of the same compound in flowers, except for the content of amentoflavone, which is independent in these two parts. Rutin and hyperoside are in positive correlation, and quercitrin is in negative correlation with the altitude of the growing site.