Abstract: The trace amounts of Fe, Ni, Cu, Cd and Pb were determined in 73 selected human blood samples collected from seven groups of general population including normal and diseased persons. Atomic absorption spectrometric technique was used for these measurements. Iron and Cu were found in variable amounts in almost all samples studied. Among toxic metals, Cd was found negligible in all groups whereas, Pb was present in relatively high concentration. Elevated level of Ni was noted in few samples only. The correlation of these metals to age of the group members was calculated statistically. Possible sources of blood contamination by the toxic elements, their adverse impacts on human health and the diseases caused by the excess or deficiency of essential trace elements were also considered.