Lead is the most frequently quantitated toxic metal in biological matrices. We describe methodologies for lead determinations in whole blood and urine using Zeeman effect flameless atomic absorption spectroscopy. The whole blood determination requires a simple aqueous 1:10 dilution while the urine lead methodology utilizes a twofold dilution with 5% nitric acid. Within-run relative standard deviations (RSD) for the whole blood determination are approximately 4. 9%, while urine lead within-run PSD's are approximately 6.7%. Detection limits for both the whole blood lead determination and the urine lead determination are 3 ppb. Linearity for both assays is to 200 ppb in the diluted specimens.