The proof of accusation is a topic of critical importance for the crimes of defamation. One of the problematic areas in that context is whether a derogatory and hurtful behaviour can be made against others on the basis of matters which are factually correct. As a rule, the proof of accusation constituting crimes of defamation is prohibited under Turkish criminal law, and the fact that the accusations that constitute the crime of defamation reflect the truth does not affect the punishment of the act. However, if the conditions stipulated in article 127 of the Turkish Criminal Code are fulfilled, the accused may be given the opportunity to prove his accusation, and if he proves it, he would not be punished for the relevant act. The proof of the accusation is also regulated in article 39 of the Constitution. However, it is observed that article 127 of the Turkish Criminal Code does not fully correspond with article 39 of the Constitution. Under the Constitution, the proof of accusation is recognized as an absolute right without any conditions in terms of the accusations against those who carry out public duties and services. Whereas article 127 of the Turkish Criminal Code does not include such an explicit regulation for those who carry out public duties and services.