Foodborne diseases in nature are usually infectious or toxic, caused by bacteria, viruses, parasites or chemicals, transmitted through food or water contaminated by the human body. To control the disease, as well as to ensure that the food is safe and healthy, its risks must be checked, detected and controlled. The goals of food industry are to produce healthy and high quality products that requires no contamination with bacteria. The use of natural preservatives such as herbal extracts and essential oils is recommended. Allium atroviolaceum is a family of Alliaceae and is a perennial herb which has a high nutritional value. The role of plant extracts has been evaluated as a preservative. The total number of bacteria calculated followed by treatment of the aqueous and ethanol extractions of the A. atroviolaceum on rainbow trout fish fillet. 100 µl of aqueous and alcoholic extracts followed by ten times dilution used to evaluate the minimum inhibitory concentration, then 25 grams of rainbow trout fillet was submerged with the best concentrations of aqueous and alcoholic extracts.  The results illustrated that the best aqueous and alcoholic extractions against Staphylococcus aureus was 3.125 mg ml^-1 and 6.25 mg ml^-1 and followed by treatment on fish both type of extraction showed inhibition on growth of bacteria compare to control group. So we believe that this plant has such a valuable effect to improve the quality and shelf life of fish.