In humans, the Apelin gene is located on chromosome Xq25-26.1 and it encodes a 77-aminoacid prepropeptide. Considerable sequence homology exists across different mammalian species. Apelin is emerging as an important regulator of cardiovascular homeostasis but, at present, few data from humans are available and further studies are necessary to better define its role in cardiovascular pathophysiology. The role and function of Apelin in cardiovascular system could be reliably investigated in experimental models devoid of confounding effects reflecting only the natural history of the disease. The pig constitutes a model largely used in experimental pathology where it has a central role in "in vivo" clinical settings. Sus Scrofa genoma is not completely sequenced and Apelin gene is still lacking. Aim of this study was to sequence the Apelin in Sus Scrofa for future applications to molecular biology studies. Using the guanidinium thyocyanate-phenol-chloroform method, we extracted total RNA from samples obtained from heart of mouse and from atrium and ventricle of normal pigs. Pig Apelin mRNA was sequenced using polymerase chain reaction primers designed from mouse consensus sequences. A partial sequence of Sus Scrofa Apelin mRNA, 1-201 pb, was submitted to GenBank (accession number FJ362603). The bands obtained from pig cardiac tissue shared a 99% sequence identity with Mus musculus and 90% with Rattus norvegicus. The knowledge of Apelin sequence can be an useful starting point for future studies devoted to better understand the possible alterations of Apelin mRNA expression in different cardiac diseases.