Pelargonium endlicherianum Fenzl. (Geraniaceae) is one of the important species of Pelargonium growing in Turkey. The purpose of this study was to evaluate the antimicrobial activities of P. endlicherianum roots on medically important microorganisms. The antimicrobial activities of 11% ethanol and 70% methanol P. endlicherianum extracts against various bacteria and yeast were studied using the agar dilution method at concentrations ranging from 0.375 to 30.00 mg/ml. The minimum inhibitory concentrations (MICs) of P. endlicherianum extracts against some microorganisms was determined. The highest inhibition was exhibited against Staphylococcus aureus by the 70% methanol extract of P. endlicherianum at 1.38 +/- 0.36 mg/ml. The results of this study suggest that P. endlicherianum extracts possess antimicrobial activity against some of the tested microorganisms.