Summer droughts induce strong declines in forage yield in mountain grasslands. The aim of the DryMount project is to determine the most suitable mixtures that can provide satisfactory forage yield under drought. Three species-rich mixtures co-dominated by Alopecurus pratensis and Dactylis glomerata and differing in their expected proportion of drought-resistant species (DRsp, 0, 15, 30%, including Plantago lanceolata, Lotus corniculatus, Agrostis capillaris and Festuca rubra) were sown in 2023 with four replicates at four mountain sites (around 1100 m asl) with different pedoclimatic conditions across Switzerland. In the two harvests of the sowing year, drought-resistant species abundancesignificantly impacted forage yield. At the drier sites, the mixtures with DRsp had higher yields than the mixtures without DRsp, whereas at the wetter sites they showed similar yields than the mixtures without DRsp. Overall, at the first harvest, all forage mixtures showed good nutritive value in terms of crude protein, fibre and sugar content, with differences mainly observed among sites. However, mixtures with 30% DRsp had higher sugar and lignin contents than the other mixtures. Altogether, these preliminary results highlight the benefits of drought-resistant species for forage yield under drought without any major reduction in nutritive value during their establishment in the year of sowing.