New mixtures of forage plants are needed to rehabilitate degraded lands and to improve productivity of Mediterranean pastures. Eight mixtures of 1 to 5 annual legumes (Trifolium subterraneum sensu latu, Medicago polymorpha, T. michelianum, Ornithopus spp. and Biserrula pelecinus) were compared during three-years in Sardinia (Italy) and Cauquenes (Chile). Subterranean clover accounted for 75 per cent of all mixtures. After sowing, plant density was higher in Sardinia than in Chile. The contribution of T. michelianum, Ornithopus spp. and B. pelecinus to botanical composition and forage production was always negligible, suggesting a lack of competition towards subterranean clover. The contribution of M. polymorpha to dry matter production exceeded the percentage of seed doses (6.2-25 per cent) and grew from 15 to 50 per cent compared with the original contribution. In general, dry matter production, seed yield and autumn reseeding for subterranean clover and annual lucerne were higher in Sardinia than in Chile.