The purpose of this research is to investigate the fair trial for people with multiple citizenships in an analytical-inferential research method, and the method for information collecting is library method and note-taking method. The considered statistical group includes people with double or multiple citizenships who need a fair trial in international courts. A partial look at the conditions of proceedings of people with multiple citizenships in Iran and along with it a brief look at the legal field of the research in a way that was done in order to get to know the subject. Regarding this issue, the type of research is in the category of theoretical and descriptive-analytical research. Therefore, the library method will be used considering that the most common method of collecting information in general researches is the library method (documents). And for collecting information note-taking method with note taking from the sources will be used to carry out the research in a practical way. Also, by examining how the international laws of people with multiple citizenships are obtained under fair trial, and by analyzing the legal effects of multiple citizenships, "conclusions" and research proposals and providing solutions are discussed.