This study was designed to evaluate the effect of mustard flour, garlic powder and acetic acid either individually or in combined effects on Salmonella typhimurium. Samples treatments were prepared to achieve various concentration by addition of 5% and 10% of mustard flour and garlic powder, while acetic acid was added by 0.5% and 1%. The treatments were added to ground beef samples after inoculation with Salmonella typhimurium and stored at 4^° C.Samples were followed up after 0, 24, 48 and 72 h. The obtained result indicated that garlic powder showed the greatest antibacterial activity followed by acetic acid then mustard flour which showed lowest and slowest reduction rate of the tested organism. All combining effect showed remarkable reduction rate where salmonella typhi can't be detected after 24 h of inoculation in combining effect of mustard 5 %, garlic 5 % and acetic acid 0.5% also in mustard 10%, garlic 10% and acetic acid 1%.