One of the major and more controversial matters in international arena is international peace and security. This matter becomes more controversial when it relates to the international criminal tribunals. In other words, the term of “tribunal” itself in international relations raises inherently the conflict between peace and justice. It means that this basic question may be made whether there is any conflict between international peace and security and justice?Moreover, a tribunal which, in principal, is seeking to apply and realize justice, in the case of any conflict between peace and justice, to which it may give priority? Or such a question may not arise at all. This research, therefore, deals with the role of the international tribunals to maintain and restore the international peace and security. It is necessary, so, to review the different generations of international criminal tribunals/ courts and the relationship between peace and justice.The international society, surely, is seeking both to maintain international peace and security and apply justice in long time. The society, therefore, tried to use all available instruments to achieve such purpose. This has been done sometimes by the victorious states after armed conflicts, and sometimes by the UN Security Council. These courts have done their role to maintain international peace and security through trying, sentencing and imposing punishments against the responsible persons. They also achieved this purpose via prevention of the future crimes and rule of law, which is precondition for peace.