In this study, a conductimetric titration method is proposed for the determination of some commonly used antibiotics. The conductimetric titration of three antibiotics, namely ampicillin, amoxycillin trihydrate and rifampin, was carried out in acetic acid using perchloric acid as titrant. Ciproflaxacin hydrochloride, however, was titrated after being dissolved in acetic acid containing an excess of mercury(II) acetate. For the titration of netilmicin sulphate, barium acetate prepared in acetic acid was used as titrant. The method was found to be highly accurate and precise, having a relative standard deviation of less than 1.0% for all antibiotics studied. It was also shown that the conductimetric titrimetry could be successfully applied to the assay of commercial preparations containing the above-mentioned antibiotics. The validity of the method was tested by the recovery studies of standard addition to pharmaceuticals and the results were found to be satisfactory.