The current goal of this study is a phytochemical analysis of a Sempervivum ruthenicum Koch ethanolic extract, in order to find potential medical applications. The ethanolic extract was prepared from the dried leaves of the plant by maceration in absolute ethanol. Total phenolic content was assessed with a slightly modified Folin-Ciocalteu method. A HPLC analysis was conducted and the total antioxidant activity of the extract was assessed with a DPPH method. The total phenolic content of the extract was calculated at 1.0344 ± 0.0237 mg/mL. After conducting the HPLC analysis on the ethanolic extract, phenolic acids, flavonoids and glycosides were identified and quantified. The most prevalent phenolic acids in the extracts were gallic and ellagic acids, with concentrations of 0.5137 ± 0.0110 mg/mL, respectively 0.3139 ±0.0046 mg/mL. The glycoside astragalin is also present in relatively high concentrations, of 0.0929 ± 0.0049 mg/mL. The EC value for the ethanolic extract was 4.6112 ± 0.08 mg/mL. These results suggest a good scavenging ability of the extract, which is due to the abundance of phenolic compounds found within. The ethanolic extract of Sempervivum ruthenicum Koch harvested from the Dobrogea Region of Romania has a complex phenolic profile with high levels of gallic and ellagic acids, and a strong anti-oxidant activity which can be exploited both in traditional medicine and in phytotherapeutic preparations.