Ketoconazol (KC) and trimetazidine hydrochloride (T MH) react with tetraiodobismuthate to give ion-pair complexes. The ion pairs are readily extractable i n 1, 2- dichIoroethane to give a reddish orange colour with maximum absorption at 491nm that can be used for q uantitative spectrophotometric analysis. By applica tion of the methods of Sommer and Job involving non-equimolar s olutions, the conditional stability constant (log K - )of the KC-BiI 4 ion pair (1:1) at the optimum pH of 2.5 and 0.075 M KI, was found to be 5.81. The mean recoveries for a uthentic samples of KC and TMH were 99.98 ± 0.39 an d 100.05 ± 0.51%, respectively. Alternatively, dete rmination of the bismuth content of the ion pairs via atomic absorpt ion spectrometry (AAS) provides an indirect method for the determination of these drugs. The mean reco veries were 99.83 ± 0.71 and 99.92 ± 0.78% for KC and TMH, respective ly. Both methods were applied for the analysis of p harmaceutical preparations and the results obtained are comparable to the reported methods.