Perennial grasses are an important source of feed, but also a substrate for the production of renewable energy. We studied the quality of the freshly harvested biomass of Romanian cultivars of tall fescue Festuca arundinacea : Adela, Brio, Măgurele 5, created at the Research-Development Institute for Grasslands, Brașov, and cultivated in the experimental plot of the National Botanical Garden (Institute) „Alexandru Ciubotaru”, Chisinau, R. Moldova. The samples for assessment were taken in the 2nd year of growth, when the plants were cut for the 1-st time. The amount of dry matter (DM), organic matter (OM), crude protein (CP), crude ash (CA), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), cellulose (Cel), hemicellulose (HC), the digestibility of dry matter and organic matter, feed value and biomethane production potential were analyzed. It has been determined that the fresh mass of the tall fescue cultivars contained 23.4-25.8 % DM and the dry matter contained 114-136 g/kg CP, 74-89 g/kg CA, 582-593 g/kg NDF, 356-366 g/kg ADF, 34-37 g/kg ADL, 322-329 g/kg Cel, 226-229 g/kg HC, 60,3-63,8% digestible dry matter and 57,2-62,2% digestible organic matter; this fact indicates a good quality of the natural feed for ruminants. The substrate for the anaerobic digestion consisting of fresh mass of tall fescue had a biomethane production potential of 349-354 L/kg of organic matter. The studied cultivars of tall fescue could be used in the Republic of Moldova for the restoration of degraded permanent grasslands, as a component of the mix of grasses for the creation of temporary grasslands and can be planted between rows in vineyards and orchards. Besides, the obtained biomass can be used as feed for animals or as substrate at biomethane production plants.