Instrumental Neutron Activation Analysis /INAA/ has been employed for the determination of 15 major, minor and trace elements in human and animal blood samples. Dry whole blood samples along with NBS and IAEA standards were irradiated for 5 min, 1 h, 5 h and 10 h with reactor thermal neutrons and counted using high resolution -spectrometry at successive intervals. Data for a new IAEA proposed CRM Mixed Human Diet /H-9/ is reported.