The effect of adding different levels of fat replacers either "Dairy Lo" or "Maltrin" on the quality of nonfat yoghurt was studied. "Dairy Lo" or "Maltrin" were added to nonfat milk yoghurt at levels of 0.5 and 1%. Results showed that addition of fat replacers did not significantly affect the chemical composition of resultant nonfat yoghurt and increased the soluble nitrogenous compounds, formation of acetaldehyde, diacetyle and total volatile fatty acids (flavour compounds). Also, addition of fat replacers, improved rheological properties: (syneresis and viscosity of yoghurt). On the other hand, addition of both "Dairy Lo" and "Maltrin" increased the organoleptic properties of yoghurt. Maltrin was more effective in this respect. Overall, the nonfat yoghurt containing 0.5 and 1% Maltrin was similar in quality characteristics to full fat control yoghurt. So, it could be recommended using some fat replacers especially Maltrin to improve the flavour formation and body characteristics of nonfat yoghurt.