As is common knowledge, tourism, in addition to being a complex and multidimensional phenomenon, is comprised of several subsystems that are interdependent and form a unified whole. This tourism system is influenced by numerous environmental forces, including economic, social, ecological, technological, and political factors. Consequently, the study and interpretation of a general view of tourism development in developing countries, particularly in the least developed and least developed countries, necessitates, without exception, an inter-disciplinary team. In the context of the research conducted, an attempt was made to evaluate both the positive and negative effects of tourism development on the economies of developing countries, including not only those that have already completed the prerequisite development stage, but also those that are during it and have a deficient development level: the least developed countries. Through an examination of the historical and theoretical evolution of tourism as an economic activity, it was possible to identify the promoting and inhibiting factors of tourism development and, most importantly, to document, with the aid of international literature, the conditions under which tourism can develop and contribute to the economic growth and progress of developing countries in general. Particular attention was paid to the efforts of many less developed countries to develop their tourism in order to use it as a lever for their economic development, and policies and measures are proposed to contribute to the achievement of this objective. Bibliographic research to gather the necessary information from the international literature, empirical investigation of the conditions and prospects of tourism development in the least developed countries to strengthen their effort to break the vicious cycle of poverty and misery that plagues them, and econometric approaches to examine the effect of certification on tourism development are the research methods chosen and utilized for the execution of this work.