The medical science of the Qajar period was in the continuation of Iranian traditional knowledge and despite the familiarity of Iranians with new sciences, including modern medical knowledge, there were many obstacles and problems in the path of medical progress, and therefore there was not much change in the traditional methods of this science and Iranian doctors They treated patients in the way of the past and with non-scientific methods. This research aims to investigate the obstacles and problems of medical progress in the Qajar period in a descriptive-analytical way, relying on library sources and referring to the travelogues of Europeans, and answers the question of what are the factors in the regression and non-advancement of treatment methods. Were they effective in the Qajar era? The findings of this research show that the main aspect of Iranian medicine in the Qajar era was traditional and ineffective. The main reason behind the backwardness of medicine in this period is the superstitious beliefs prevailing in the society, the utilitarianism of traditional doctors, not changing the level of the attitude and views of the common people to the progress of medical science in other parts of the world, and the obstruction of profit-seeking people, and finally, the lack of effort and ability of the government. Qajar was to spread modern medicine in the society.