Introduction: The remarkable development of Molecular Biology since the mid-twentieth century has profoundly impacted biomedicine, among other life science disciplines. This development was possible only by elucidating the molecular structure of deoxyribonucleic acid (DNA). Objective: To highlight the importance of solving the structure of DNA in celebrating seventy years since its discovery. Material and Methods: The writing methodology was the historiographic method: A comprehensive analysis of articles and books relevant to a specific topic that provides a knowledge base. The search included several databases and books. The approach to writing was a traditional mixed narrative review, integrating some chronological and critical evaluative review elements. Results: Several scientists participated in an intense race to solve the DNA structure, the “key molecule” of heredity. The elucidation of DNA structure, with the consequent proposal of the Watson and Crick Model in 1953, was based on a sequence of scientific events. This finding led Molecular Biology to its Golden Age and originated Structural Biology. Philosophy of Science was also impacted by this finding, especially regarding paradigm changes, the ascription to the new double helix model, and the consequent revolution in all biological sciences. Conclusions: DNA structure elucidation, equivalent to unravelling one of the “secrets of life”, had a profound impact on biological and health sciences, currently changing the way of addressing various genetic issues in biomedicine. Thanks to the discovery of DNA structure, the foundations were laid for human genome sequencing twenty years ago, which meant the beginning of the Postgenomic Era.