Both Greece and Turkey have been at the frontline of irregular migration to Europe for several years. This seminar discusses findings on how migrants make the decision whether to stay in the country of transit (Greece or Turkey) or migrate onwards. The majority of a limited academic literature on migrant decision making has been concerned either with the decision to migrate in the first place (for example distinguishing voluntary from forced migration), or the decision whether to return. Decision making in transit has not been explored in depth. Migrant decision making in transit can is influenced by conditions in the country of origin, conditions in the current country of stay (transit country), conditions in the perceived destination country, individual and social factors, and policy interventions. This paper considers these multiple factors in the analysis of 1,028 surveys with migrants from Afghanistan, Iran, Iraq, Pakistan and Syria collected in Athens and Istanbul in spring 2015. Regression analysis has been used to predict the factors determining the desire of migrants to migrate onwards as compared to stay in the current country or return.