Due to improving technology and global competition today sky is the only limit for high towers of metropolitan areas. The increase in number of high rise has been ruining the silhouette of cities all over the world like Istanbul, whose identity and image have also been destroyed by skyscrapers dominating the seven slopes on which it was once built. The urbanization in Istanbul has somehow become homogenous and destructive over the topography. Despite of raising debates on the critical issue now and then, no analytical approach has ever been introduced. The research therefore, aims to analyze the change of Bosphorus silhouette caused by the emergence of high rise blocks in Zincirlikuyu-Maslak route since it was defined as a Central Business District and a high rise development area by Bosphorus Conservation Law in 1991. ArcGIS Desktop software and its analyst extensions are used for mapping, analyzing and evaluating the urban development within years. The application is considered to be the initial step for a decision support system which will assist in assigning ground for high rise buildings in Istanbul.