The invention relates to human procalcitonin and the preparation and use thereof. In particular, a process for preparing human procalcitonin is described wherein a gene coding for a polypeptide comprising the amino acid sequence of human procalcitonin is inserted into a vector; a host organism is transformed with this gene-containing vector; and the polypeptide expressed by the host organism is isolated. Furthermore the use of the polypeptides according to the invention, in particular as medicaments and diagnostic agents is described.