This work deals with the important role played by the writer Leopoldo Lugones in the creation of a sub-genre of literature called Hard Science Fiction. Leopoldo Lugones is, from our perspective, the first international exponent of this rigorous science fiction, and here we intend to expose data to justify it. This subgenre presents science as the main element of the plot, and puts all its emphasis on descriptions of technology and/or a very advanced science ―millimetric sometimes―, of the scientific and technical descriptions. Without detracting no merit, the proximity of the writings by Jules Verne to the adventure novel may relegate him to the role of first inspiration of what later would become Hard Science Fiction subgenre. We believe that his Voyage au center de la Terre  is a novel that combines a perfect hybridization of genres. Additionally, our opinion is that Leopoldo Lugones, with some of his stories which later would be reflected on Las fuerzas extrañas , was the first author to be classified as a writer of this subgenre. In order to justify this view, it will be used the defining characteristics of this style already offered by great scholars such as R. Scholes, or David Harwell, which will be added to our contributions.