Neuropeptide Y (NPY) is a member of the pancreatic polypeptide family. It plays a critical role in the regulation of satiety, reproduction, the central endocrine and cardiovascular systems. The T1128C polymorphism of human NPY gene has been shown to be associated with many cardiovascular diseases. The allele frequency of the 1128C was investigated in 6626 subjects from Europe, North-America, South-America, Asia and the Middle-East. The 1128C allele was observed in all populations of European descent and the Israeli population, with a mean frequency of about 4%. The allele frequency showed a geographical north to south gradient of decreasing frequency. The highest allele frequencies were found in Nordic countries. The NPY 1128C allele might originate in the north of Europe, and then spread to neighboring regions.