In live animals, lead poisoning can be diagnosed by analyzing blood samples. For postmortem testing, blood samples are not available and analysis of liver or kidney is often used for diagnosis. Liver and kidney analysis is relatively expensive and results might not be quickly available. We examined an inexpensive, rapid method to screen animals for lead toxicosis postmortem by testing the mixture of body fluids (termed "tissue fluids") that pool in the body cavity at necropsy for lead. At necropsy we collected body fluid and liver samples from Common Loon (Gavia immer) and Bald Eagle (Haliaeetus leucocephalus) carcasses and determined concentrations of lead in tissue fluid using a desk-top blood lead analyzer. Concentrations of lead in liver were determined by inductively coupled plasma mass spectroscopy. There was strong correlation between tissue fluid and liver tissue lead concentrations, and receiver-operating characteristic analysis gave an area under the curve of 0.91, indicating that postmortem measurements of lead in tissue fluids can be utilized as a screening method for lead toxicosis.