In a fatal (cardiotoxic) case of oleander extract poisoning of a young female, ethanol extracts of blood and tissue homogenates were purified by lead acetate. After removal of excess lead by ammonium sulfate, oleandrin was extracted into chloroform. Oleandrin in the extract concentrates was detected by thin-layer chromatography, with location by fluorescence and chromogenically by means of p-anisaldehyde. Quantitation was performed on dried extracts reconstituted in water/methanol, reacted with hydrogen peroxide, ascorbic acid, and hydrochloric acid, and analyzed by fluorescence spectrophotometry. Excitation was at 355 nm, and fluorescence scanning from 340 to 580 nm. The fluorescence peak at 460 nm was used for the quantitative measurement. The concentrations of oleandrin measured in blood, stomach wall, colon tissue, liver, heart, lung, brain, spleen, and kidney ranged from 10 to 39 micrograms/g, with 200 micrograms/mL in the total gastric content residue submitted for analysis.