In metropolitan areas, the changing spatial land-use preferences of the industrial sector are the most important determinants in the forming of the macro-form. Metropolitan areas, especially in developing European and Asian countries, become troubled cities with agglomerations of population and investment as a result of failures to apply satisfactory macro-policies and plans throughout the country. Industrial investments on various scales and the land-use preferences of investors have changed over time. The land preferences of production and headquarters of the manufacturing sectors have become basic determinants in the formation of settlement systems due to the transformations that occur alongside technological, economic and social development. This article examines whether or not the basic land-use criterion of the manufacturing sector changes in small-, medium- and large-scale businesses according to their labour structure, defined through an examination of the sectoral structure and relations of scale. Taking the increasing rate of the Gross National Product of the industrial sector in metropolitan areas in every country into account, and examining the land-use preferences of various industrial sub-sectors and scales will serve as an important input when making new planning decisions. The industrial land-use criterion will be effective in the transformation, reorganization or directing of new focuses for the agglomerated industrial structure, especially in Istanbul, which features both Asian and European metropolitan area characteristics. This article will define the existing industrial structure of the Istanbul metropolitan area; and differences between the various scales of land-use preferences within industrial investments will be presented, based on the findings of two investigations carried out over a 5-year period. Several important criteria for industrial investors seeking to establish themselves in metropolitan areas will be determined in the article.