A simple and rapid method for quantitation of oleandrin in human blood has been developed using an Extrelut column and high-performance liquid chromatography (HPLC). Blood samples spiked with oleandrin were mixed with distilled water and applied to an Extrelut column for elution with ethyl acetate before HPLC. The HPLC separation of the compound from endogeneous impurities was generally satisfactory with the use of a reversed-phase column. Oleandrin showed excellent linearity in the range of 0.05-10 micrograms/g and the limit of detection was 0.02 microgram/g for human blood. The recovery of the compound, which had been spiked to human blood, was more than 90%. The present method is simple and more rapid than those so far reported, and seems useful for analysis of oleandrin in the cases of oleander poisoning.