This study presents field research about policy implementation to manage and minimize irregular migration in the border region of Van province in eastern Turkey. For this purpose, this article finds out how street-level bureaucrats at the Turkish-Iranian border perceive and deal with irregular migration. The conceptual framework covers the evolving use of Lipsky’s (1980) street-level bureaucracy approach in the public policy literature. The field research comprises interviews with a total of thirty-two border bureaucrats as street-level bureaucrats in the province of Van on the Turkish-Iranian border. Then, in the findings, six issues came to the fore in the implementation of border policy on irregular migration: the geography and climate, the intervention, the institutional relations, the judicial legislation, the physical and technological measures, and the role of the Iranian State. Finally, the discussion evaluates and reveals a “vicious circle of border security” that reduces the effectiveness of the policy implementation.