Abstract: "Gambir" (Uncaria gambir Roxb) used in this study was taken from 50 Kota Distric, West Sumatera, Indonesia, which was extracted by ethyl acetate. The antioxidant and antimicrobial activities of gambir extract were investigated. The antioxidant activities (IC50) of gambir extracts which were evaluated by DPPH (1,1-diphenyl-2-picrylhydrazil) method, were 25.55 μg/ml and ascorbic acid was used as standard. Disc Diffusion Method was employed to evaluate the antimicrobial activity against some Gram-Positive bacteria (Staphylococcus aureus) and Gram-Negative (E. coli and Salmonella sp). Rendang was made with gambir extracts with level: 0, 0.25, 0.5, 0.75 and 1%. The data obtained were processed statistically, if the treatment shows significant results (p<0.05) then further tested by Duncan's Multiple Range Test (DMRT) with SPSS methods. The organoleptic test showed that addition of gambir extracts in Rendang was not significant (p>0.05) and could extend the shelf-life of Rendang.