Ammonium reineckate(I), sodium nitroprusside(II), potassium ferrocyanide (III), nickelthiocyanate(IV), and cobalt thiocyanate (V) were used for the conductometric assay of amikacine sulphate (Amik), neomycin sulphate (Neom) and Vancomycin hydrochloride, (Vanc) through ion-pair complex formation. The effect of solvent, reagents concentration, time and temperastureon the shape of the titration curves, are studied. Themolar combining ratio is also investigated. Statistical treatment of the experimental results indicates that the method is highly accurate and precise. The accuracy of the method is indicated by excellent recovery (98.6 – 100.9%) and the precision is supported by the low standard deviation value <0.09. The sensitivity of the proposed methpod is discussed and the results are compared with the official method involving microbiological procedures. Egypt J. Anal. Chem., 12, 73–78 (2003).