This article presents the results of the first part of a study about the development of the internship in Colombian medical education. This first part offers a historical-chronological verview of the birth and development of the “internship” in European and North American medical practice, covering the period of time that begins with its appearance during Napoleonian government in France during the 19th century, and its transformation with the model proposed during the flexnerian reform in the United States at the beginning of the 20th century, as a starting point for the understanding of the Colombian case.