The book you hold in your hands is the first Turkish translation of Hippocrates' work “On Epidemics I,” widely regarded as the pioneer of evidence-based medicine today. The book presents information on the course of the disease and patient survival rates based on observational approaches to the disease processes of 14 cases, mostly consisting of patients with fever, during the epidemic that emerged during Hippocrates' lifetime, as well as records of experiences related to the mistakes made. In terms of content, it emphasizes the principle of “primum non nocere,” or first, do no harm, and also highlights the clinical approach that has survived to this day by emphasizing the principle that “there is no disease, there is only the patient” with the statement, “The conditions under which we evaluate diseases vary according to the disease, the characteristics of the patient, the treatments applied to the patient, and the people who apply them.” It is also a valuable observation that it pointed out approximately 2500 years ago that cases caused by epidemics, such as the COVID-19 pandemic we are currently experiencing, show different clinical presentations and courses. We believe that this work, which every individual in the field of medicine and health will enjoy reading, will develop the ability to connect and compare the past with the present and take our horizons one step further.