[Writing an original research article].

Publication of a scientific work is the final and obligatory stage of any research. Among the various existing types of medical publications, the research original article is the prototype of scientific article. Its finality is to communicate the investigation undertaken to the reader in a coherent, clear and precise manner. With that purpose, the discoveries found by the authors as an answer to a hypothesis are presented and discussed. To send the original article to a biomedical journal, the manuscript should present some adequate formal characteristics, in addition to contain scientifically valid information. That can be achieved by complying with the rules past by the International Committee of Biomedical Journal Editors which have been adopted by a great number of scientific journals as publication requisites. The objective of this article is to describe the structure of the various parts (first page, abstract, introduction, material and methods, results, discussion, and bibliographic references) that constitute the format of the research original article, exposing the main adverse to be avoided during its preparation.