One of the western states of the Qajar territory, which attracted the attention of the Qajar government due to the diversity of its geographical conditions, its location on the Mesopotamia and the Holy shrines commercial highway, and its borders with the ottoman Empire, was the state of Kermanshahan. Due to the lack of proper health conditions, this state sometimes suffered from epidemic diseases such as cholera. This research, with a descriptive- analytical approach and using library sources and historical documents, seeks to answer the question of what factors did cause the outbreak of cholera in Kermanshahan during the Qajar era? The results of the present research showed that the outbreak of epidemic cholera frequently occurred in Kermanshahan province, and factors such as the lack of accountability of agents, the inefficacy of some local governors in controlling the disease and the lack of a prevention plan, lack of knowledge of new treatment methods, public ignorance and promotion of superstitions, lack of trust in the treatment methods of European doctors and insistence on treatment through traditional medicine, fake reports and statistics of government officials, lack of basic and appropriate quarantine and lack of attention of the central government played an effective role in controlling the disease