The effect of adding dried mushroom powder as a source of antioxidants and fiber at level 1.0, 2.0 and 3.0% on physiochemical and sensory properties of low-fat yoghurt was studied. The properties of yoghurt samples including pH values, titratable acidity, syneresis, viscosity, dietary fiber, total phenolic content, antioxidant activity and sensory properties were determined when fresh and during storage for 15 days at 5-7°C. Results showed gradual increase in pH values, dietary fiber, viscosity, phenolic content and antioxidant activity as mushroom powder ratio was increased. On the other hand, the acidity and synersis were decreased as the ratio of mushroom powder increased. Low- fat yoghurt supplemented with up to 2% dried mushroom powder had similar appearance, flavor, texture, and overall acceptability as control of full fat yoghurt.