The in vitro activity of propolis against 118 Staphylococcus aureus, 108 Escherichia coli, 60 Salmonella typhimurium, 50 Candida albicans, 23 Candida parapsilosis, 19 Candida tropicalis and 14 Candida guilliermondii isolated from human infections was studied by the agar dilution method. Among the bacteria, the Gram-negative were the least susceptible organisms showing minimal inhibitory concentration (MIC) for 90% of the strains tested ranging from 22.5 mg/ml - 10,2% V/V to 23.1 mg/ml - 10.5% V/V. The MIC's for Candida ranged from 0.80 mg/ml to > 11 mg/ml (0.40% V/V to > 5.0% V/V), the strains of C. parapsilosis being the least susceptible. The relative order of susceptibility among all isolates, was: S.aureus > C. tropicalis > C. albicans > C. guilliermondii > C. parapsilosis > S. typhimurium > E. coli.