The aim of study was to produce a low-fat cacao containing probiotic yogurt. For this reason a combination of probiotic bacteria, lactobacillus acidophilus and Bifidobacterium lactis (3% w/w) together with 0.8% cacao powder, 5% sugar as a well as 1.2% cacao powder with 7% sugar were used to produce a synbiotic yogurt (0.5% and 1.5% fat). Populations of probiotics bacteria, physiochemical and sensory properties of the yogurt samples were evaluated throughout the storage period (1, 7, 14, and 21 days). Result showed that cacao as prebiotic could significantly increase the viability of L. acidophilus (P<0.01), besides no significant difference was observed between the populations of B. lactis in the CHOCOLATE yogurt and control samples. The highest quantity of the probiotic bacteria was observed at day 7, followed by a decrease in their number, however their populations remained above 7 log cfu/g. Moreover, pH value of the samples decreased over the time of storage, but pH value of the cacao-containing samples increased significantly (P<0.01). In comparison with the control group, no significant increase was recorded in the lipid content of the samples with cacao and sugar, meanwhile the amount of dry matter was higher than control samples (P<0.01). It could be concluded that apart from the prebiotic properties of cacao on L. acidophilus, it can improve the nutritional value of probiotic yogurt and increases the calorie of the product. However for achieving better sensory properties, changes should be considered in the formulation.