Abstract: Methods for the determination of cisplatin (I), oxoplatin (II), carboplatin (III), oxaliplatin (IV) and tetraplatin (IV), in human plasma ultrafiltrate and urine (100 l samples) are described). For I, an MCI gel CDR10 column (8 cm x 4.6 mm i.d.) was used with 10 mM acetate buffer of pH 5.5 containing 0.1 M Na2SO4 and 30% acetonitrile as mobile phase. For II a MCI gel CPK08 column of similar dimensions was used with 50 mM K2SO4 as mobile phase. For III, IV and V and Inertsil ODS-2 column (25 cm x 4.6 mm i.d.) was used with 10 mM acetate buffer of pH 5.5 containing 5% acetonitrile as mobile phase. The flow rate was 1 ml/min and the columns were operated at 40°C. Post-column reaction at 60°C and 0.3 ml/min was performed with 40 mM NaHSO3 in 10 mM acetate buffer of pH 5.5 in a reaction coil (10 m x 0.5 mm i.d.) for detection at 290 nm. The calibration graphs were linear for 0.05-20 M-I, 0.1-20 M II, and 0.2-20 M III, -IV and -V and the corresponding detection limits were 20, 40, 60, 100 and 60 nM; the intra-day RSD were <5%. The recoveries were >>95%. The method was used to study the pharmacokinetics of I and II in rabbits.