In this study, the effects of β‐glucan from two different cereal sources (barley and oat), as prebiotics, on the viability of Bifidobacterium animalis subsp. lactis strain Bb‐12 in probiotic set yoghurt and the properties of yoghurt were studied. Physicochemical properties of yoghurt samples (including pH, titratable acidity (La%), whey separation, organic acids such as lactic and acetic acid, colour (L*, a*, b*, ΔE, C*, h*) and sensorial properties) were significantly affected by the addition of barley‐ and oat‐based β‐glucan. As a result, the survival of B. animalis subsp. lactis was maintained within probiotic and therapeutic levels (>7 log cfu/g), due to the possible prebiotic effect of barley‐ and oat‐based β‐glucan, after 28 days of cold storage of the probiotic yoghurt. In conclusion, β‐glucan can be used for the development of cereal‐based functional dairy products with sufficient beneficial effects, probiotic viability and acceptable sensory characteristics.