Abstract: Probiotic micro-organisms such as lactic acid bacteria are very useful antioxidants which have potential to reduce free radicals in human body. The aim of the present study was to determine the in vitro antioxidant potential of cell free supernatant (CFS) of two probiotic bacteria i.e. Lactobacillus plantarum KP894100 and Lactobacillus acidophilus KP942831. The CFS of L. plantarum KP894100 and L. acidophilus KP942831 showed potent DPPH, superoxide and hydroxyl radical scavenging activity with concentration dependent manner when compared with ascorbic acids as standard drug. Protein contents present in CFS of L. plantarum KP894100 was 12 mg/ml and in L. acidophilus KP942831 was 8 mg/ml was determined by Lowry methods.