Finding proper milk fat substitutes for manufacturing of nonfat dairy products is a major challenge for dairy industry in order to respond the consumer' demands. Three different concentrations of tara gum (TG) and three combinations of TG with buttermilk powder (BP) were used as fat replacers for manufacturing of nonfat yogurt. Use of TG (0.25 and 0.50/gl) and a combination of TG (0.25/gl) and BP (10/gl) decreased whey separation while improved the gel firmness and viscosity of nonfat yogurt (p < .05). Denser microstructure observed in nonfat yogurts fortified with TG (0.25 and 0.50/gl) and combination of TG and BP (0.25 + 10/gl). Significant changes were observed in pH and viscosity of yogurts (p < .05) during storage. In conclusion, fortification of nonfat yogurt with specific concentrations of TG or combination of TG and BP had positive effect on quality properties of the product. Practical applications Low-fat or nonfat yogurts have been preferred by consumers in recent years because of health concerns. However, nonfat products have quality defects due to the lack of milk fat. For this purpose, TG and BP as fat replacers at different rates for the production of nonfat yogurt were used in this research. Use of TG and BP changed yogurt's physicochemical characteristics and caused relatively denser microstructures. With this study, combined use of TG and BP provided the improvement of nonfat yogurt product.