The study seeks to examine the conceptualizations of space and scale in development thinking. One of the important dimensions of the development is the conceptualization of space and scale. The mainstream development theory, which is modernization, theorizes space as a physical geographical style that is technical and measurable. Scale on the other hand conceptualized on the nation state scale. Critical development geographies approach, on the other side of the discussion, criticizes modernization and advocates defining space as a relational concept and scale as a fluid concept. Those conceptualizations were extended towards the field of development finance. In the empirical part of the study, Islamic Development Bank was investigated as a representative the critical development geographies approach since the Banks area of operation was defined according to relational spaces of development. Besides, all major Regional Development Banks and World Bank have been taken as the representatives of mainstream development thinking; yet they still conceptualize space in a physical and political geographical style. Qualitative research methods were employed in order to analyze the topic.