Abstract: The aim of this study was to investigate the bacterial inhibition and antioxidant activity of 24 and 48 h of rice milk-kefir and cow milk-kefir. Bacterial inhibition activity of kefir was investigated against Staphylococcus aureus, Bacillus subtillis, Escherichia coli and Pseudomonas fluorescens by using the disk diffusion method. Kefir showed some activity against all organisms tested. Antioxidant activity of kefir was measured using three different methods: DPPH radical scavenging activity of extracts, lipid peroxidation assay and hydroxyl radical scavenging activity. As a standard BHA (Butylated hydroxyanisole) was used. Rice milk-kefir was displayed significantly greater of antioxidant activity. These findings have suggested that rice milk-kefir may be considered among the more promising food components in term of preventing oxidative damage.