The handling of foreign nationals who have committed offenses is characterized by a problematic interplay of criminal law and immigration regulations. In the context of penal execution, this leads to significant disadvantages and stricter enforcement for foreign prisoners. This study examines when the execution authorities become aware of a decision regarding deportation and how this uncertainty affects execution planning and arrangements. The differences in personal prerequisites and the treatment of German and foreign prisoners are analyzed. Additionally, the practice of Section 456a of the German Code of Criminal Procedure is investigated, which allows for the suspension of the enforcement of a prison sentence if the convicted individual is to be deported from Germany.