Objective: Medical knowledge has begun to be built precisely on scientific methods in the nineteenth century and the gaining momentum of experimental medicine practices has led to the emergence of laboratory medicine. The second half of this century iwas a period in which the relationship between microorganisms and diseases was yet to be defined. This concept led to the development of scientific methods in the fight against epidemic diseases, and strict obeiance to asepsis-antiseptic procedures in medical and surgical applications became a necessity. Unlike the previous centuries, in this period, the concept of “hospital medicine” emerged. The first establishment of the Red Crescent and first health organizations under the name of Red Crescent Society (Hilal-i Ahmer Cemiyeti) was also realized in this period. Method: The data of 27 different health units established by the Red Crescent during the 1877- 1878 Ottoman Russian War were analyzed and a summary of available data on infectious diseases is presented in this study. Results: Approximately 61.74% of all death cases were associated with infections and the most common causes of death in patients were dysentery (n:94; 18.4%), typhus (n:88; 17.2%), pneumonia (n:62; 12.1%), enteritis (n:59; 11.5%), typhoid fever (n:50; 9.8%), bronchitis (n:42; 8.2%) and pulmonary tuberculosis (n:39; 7.6%). Conclusion: We think that these data have special importance because they are the first data about the infections and mortality rates of inpatients in the health services provided by the Red Crescent under many adverse conditions brought by war where firearms were used intensively , such as refugee movements, famine and malnutrition.