It is very hard to generate a set of criteria to separate preparatory from executive acts. This fact can be considered as a necessity. At the same time this also reflects the vulnerability of the legality principle. The distinction between preparatory acts and the executive acts is one of the most controversial issues in modern criminal law. In Turkish Penal Code, the sole criterion regarding the beginning of executive acts is reflected in Art. 35 which states”A person who (directly) acts”. This in fact is not a clear formulation and unable to answer the question of when exactly the executive acts start. Therefore, the Turkish courts, especially the Supreme Court (Yargıtay), are inspiring from the Turkish doctrine which takes advantages of various theories below, adopts and updates new measures and criteria to separate preparatory acts from executive ones.