Introduction As a consequence of the increasing mobility of highly skilled professionals, innovation-promoting, transnational cooperation and communication structures, so-called diaspora networks, emerge. The term diaspora was originally used to describe a group sharing the same language, having the same ethnicity, belong - ing to the same religion and which builds a strong joint identity and solidarity abroad. Jewish migrants are the classic example of a diaspora in the above mentioned sense (see Cohen 2008). As a result of increasing international mobility, the term diaspora has come to be used and defined in a less narrow sense, and in particular has been used to describe groups of emigrants, which maintain relations with their homeland (ibid.). In this chapter, diaspora networks are understood to be cooper ation structures of networking migrants building up communication channels and bridging the source and receiving countries, promoting knowledge transfer across national boundaries and implementing projects in the home country (see Kuz netsov 2006). The participation of strongly intrinsically moti vated people can be seen as another characteristic of successful diaspora net works. As highly skilled inter national mobile people are called “Creators of Knowledge Roads” (Maier, Kurka and Trippl 2007), diaspora networks repeal the geographical limitation of knowledge spillovers and support the generation of innovation. Therefore not only the receiving country can benefit from mobile professionals in the sense of “Brain Drain”, but also the receiving country in the sense of “Brain Circulation”. This chapter analyses the diaspora networks of highly skilled Turkish people
and identifies special characteristics of Turkish diaspora networks. The categorization of diaspora networks in a general sense will be described in the following section, after which we concentrate on the functionality and impact of diaspora networks and migration on the generation of innovation. Knowledge migration of highly quali fied Turkish people and Turkish diaspora networks in Germany are analysed, leading to a discussion of the nation-specific findings. Finally our key findings are summarized.