This study reports the potential application of yams as an efficient substrate for isolating mushrooms from the fruiting body. It seems that the utilization of yams as the medium for edible mushroom cultivation, i.e. a substitute for PDA, may increase the economic value of yams. Yams (Dioscorea sp.) belong to the starch-rich and energy-rich tubers, together with cassava, sweet potato, and potato. There is little utilization of yams in Thailand because yams grow wild and uncultivated and thus sufficient quantities of yams are available for home consumption and in local markets. In this study, an experiment was performed to assess the suitability of yambased culture media as a potentially high value material for edible mushroom isolation and mycelial growth as a substitute for potato dextrose agar (PDA). Yam-based culture media were prepared from three species (D. alata L., D. esculenta and D. pentaphylla) in varying concentrations (0, 5, 10, 15, 20, 25, and 30% (w/v)). PDA was used as the standard medium. Three edible mushrooms, i.e. Pleurotus sajor-caju (Fr.) Sing., Lentinula edodes, and Volvariella volvacea were investigated. Mycelial growth of the mushrooms was measured the average mycelium colony diameter on the different media. The results of mycelial growth of the mushrooms show that yam-based culture media can be used as alternative culture media for cultivation.