Organized Industrial Zones (OIZs) are used as a main and important industry policy tool in Turkey. In 2012, the number of OIZs is 263 with 148 active and 115 planned ones. Network between the firms reveal the knowledge spillovers which is inevitable for economic growth of a country for neo-classical economists. In this study, existence of intra-OIZ and intra-industry knowledge spillovers in Ankara and Istanbul is tested by the help of an export decision function. The data set is taken from the "Field Research Survey" of Small and Medium Enterprises Development Organization (SMEDO). According to spatial econometric estimation results; the size of the firm, technology, organizational proximity and foreign language knowledge of the administrator are the common determinants of export decision for Ankara and Istanbul for both intra-IOZ and intra-industry relations. For Ankara while for intra-OIZ relations the spatial effect is one third of the total effect, it is one fourth of the total effect for total effect for intra-industry relation. For Istanbul one fourth of the total effect is from spatial effects for both intra-OIZ and intra-industry relations.