This paper examines the role of migration-specific and migration-relevant policies in migrant decision-making factors for onwards migration or stay in Greece and Turkey. In this paper we distinguish migration-specific policies from migration-relevant policies in transit and destination countries, and in each case distinguish favourable policies from adverse policies. We test this categorisation through an original survey of 1,056 migrants in Greece and Turkey from Afghanistan, Iran, Iraq, Pakistan and Syria collected in 2015. The results indicate that, in transit countries, the policies that most strongly influence migrants' decision-making are adverse migration-specific and migration-relevant policies. By contrast, in destination countries favourable migration-specific policies appear to be more important than migration-relevant policies there in determining the choice of destination.