A method is described for the simultaneous determination of seven metals - Al, Co, Cr, Mn, Mo, Ni, and V - in blood serum using a simultaneous, multielement atomic absorption spectrometer (SIMAAC) and graphite furnace atomization. Our original intention was to determine two additional metals - Pb and Sn - however, the high ashing temperature needed resulted in premature loss of these volatile metals. Serum samples (2 mL) are dry-ashed with 20 mu L of Mg(NO//3)//2 multiplied by (times) 6H//2O (20 g/L) as an ashing aid/matrix modifier. The organic-free residue is reconstituted with 0. 5 mL of nitric acid (50 mL/L), allowing for a fourfold concentration step.