This paper seeks to investigate a new type of migration in Koohdasht city which is immigration to Tehran to carry out criminal activities. Unknown factors and the way in which these migrations take place made it necessary to use the qualitative approach in order to explore the subject matter. Grounded theory method was used to look at the field of research and achieve an emic and etic view of the problem in order to examine the conditions for the formation of this type of migration, as well as the processes and trends affecting its continuity as well as the consequences of this phenomenon. Therefore a fairly comprehensive understanding of the issue was achieved.  28 participants were interviewed through purposeful sampling. Participants included families, koohdasht residents, and drug vendors. The findings of this study gave rise to 12 different categories for families and residents and another 14 for drug vendors. The main categories emphasized in this study that were shared by all groups were the concept of the pressure of socioeconomic structures and poverty.