The aim of this investigation was to determine appropriate perennial grasses and their most suitable mixture ratios, which can be grown with alfalfa in binary mixtures. The research was conducted during 2009-2011 in Isparta (37.50 °N, 30.32 °E), located in the Western Mediterranean climate conditions. In the study, alfalfa was planted as a binary mixture with perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata L.), meadow fescue (Festuca pratensis Huds.), and smooth bromegrass (Bromus inermis Leyss.) in a randomized block design with three replications. Sowing ratios of alfalfa in the mixtures varied 20, 30, and 40%, and grass species ratios were 80, 70, and 60%. In the study, significant differences were found among the applications regarding hay yield, crude protein content, crude protein yield, NDF, ADF, land equivalent ratio (LER), and grass ratio in the hay (GR). The highest hay yield was obtained from alfalfa + orchardgrass and alfalfa + smooth bromegrass binary mixtures (25.98 and 25.78 t ha-1, respectively). Alfalfa + perennial ryegrass and alfalfa + meadow fescue mixtures gave the highest crude protein contents as 14.93 and 14.80%, respectively. The highest LER values were observed on perennial ryegrass and smooth bromegrass binary mixtures, and the highest grass ratios were determined in orchardgrass and smooth bromegrass mixtures made with alfalfa. Increasing the alfalfa sowing ratio in the mixtures positively affected all quality characteristics such as crude protein, NDF, and ADF. It was concluded that orchardgrass and smooth bromegrass binary mixtures with alfalfa produced high yield and quality hay and that the mixture should contain 40% alfalfa and 60% grass.