The effect of fortification low fat probiotic yoghurt with mango pulp fiber waste powder on the physicochemical, microbiological and sensory properties was investigated. Mango pulp fiber waste powder was added to low fat milk yoghurt at ratios of 1, 2 and 3 %. Manufacture yoghurt were analyzed at fresh and after 5 ,10 and 15 day form storage at 5 ± 1˚C for physicochemical, microbiological and sensory properties .Results showed that fortification of low fat yoghurt with mango pulp fiber waste powder increased values of total solids, protein ,ash ,pH , dietary fiber, viscosity, phenolic content and antioxidant activity and these increments were proportional to the mango pulp fiber waste powder fortification ratio . On the other hand, the acidity and synersis were decreased as the ratio of mango pulp fiber waste powder was increased. fortification of low fat yoghurt with mango pulp fiber waste powder improved the via¬bility of Streptococcus thermophiles, Lactobacillus acidophilus and Bifidobacterium bifidum and this improvement was proportional to the mango pulp fiber waste powder fortification ratio Low fat yoghurt containing of 3% of mango pulp fiber waste powder had the highest scores for sensory properties compared to other low fat yoghurt treatments .Thus, The study concluded that mango pulp fiber waste powder can be used at a rate of 3% as a source of bioactive components and dietary fiber in manufacture of low fat yoghurt which enhanced its physicochemical, microbiological antioxidant and sensory properties