The study and analysis of the social health of a society in a particular historical period has a special place. The health, diseases, and treatment status are also one of the topics in the social history that reviews the performance, thought, and behavior of individuals. Due to this problem, it is important to consider diseases, the type of treatment, the status of physicians, how to deal with modern medicine, and the government's actions and programs to prevent or treat epidemics. This article attempts to address the general state of public health in the Qajar era and the problems and consequences of modern medicine in Iran. So, the questions are as follows: What are the types of diseases and their treatment in the Qajar era? What were the obstacles to the formation of modern medicine in this period? Research findings show that the historical conditions of Iran during the Qajar era, adherence to traditional principles of medicine, the prevalence of superstitions, and the lack of new efforts and attitudes in modern medicine have been obstacles to the growth and development of public health. The research method in this paper is descriptive-analytical and most of the research findings are extracted from the notes of the travelers. However, other sources such as historiography, memoirs and documents have also been used in various forms.