The current study was carried out to evaluate the use of crude isoflavones (CIE), crude rosemary extract (CRE), butylated hydroxy anisol (BHA) and CIE plus CRE, as antioxidant and antimicrobial agents in manufacture of beef burgers during frozen storage at -18ºC for three monthes. The antioxidant and antimicrobial effects of the CIE, CRE, BHA and CIE plus CRE, were evaluated in beef burger by measuring pH, tiobarbituric Acid (TBARS) values, unsaponifiable matter, texture profile, sensory and microbiological examinations. The results showed that extracts derived from soybean (CIE) and rosmary (CRE) leaves had the potential to reduce the oxidation of beef burgers and extend their shelf life. The combination composed of 0.03% of CIE and 0.06% of CRE provided the most effective antioxidative activity in terms of TBARS values until the latter stages of storage. The combined extracts showed good antibacterial activity againist total bacterial count, coliform, staphylococous and E. coil that led also to enhance extension of beef burger shelf life. The availability of these natural antioxidants and their possible synergistic effects suggests an interesting way of improving beef burger stability to prevent the degenerative diseases caused by fat oxidation products.