The purpose of this article is to examine the issue of what are the justifiable causes of crime in Iranian criminal law and the International Criminal Court and what is the difference between these factors and the factors that mitigate criminal liability. This is a descriptive-analytical article and has investigated the mentioned subject by using descriptive-analytical method. The findings indicate that in Iranian criminal law, urgency, legal imperative, victim's consent and legitimate defense are justifiable causes of the crime and these factors in international criminal law include legal imperative, legitimate defense and urgency. Regarding the distinction between justifiable causes of crime and factors that mitigate criminal liability, the results also show that the penal law approved in 2012 did not specify the separation and distinction between the two, but the legislator in the first book of the Islamic Penal Code of 2012, under the fourth section of the second chapter It is dedicated to the obstacles of criminal liability, which implies the separation of the factors that justify the crime and the factors that mitigate the criminal liability. In international criminal law, the statute is worded mostly based on customary law and based on the broad concept of defenses, avoiding a clear distinction between the types of factors of exemption from criminal responsibility.