Favoritism is an unethical practice that is frequently encountered in institutions both in developed and developing countries. Organizational favoritism, on the other hand, is a general nomenclature given to the situation where a person or group is given privilege or advantage over others, even though it is not related to performance or competence. Favoritism can occur in different forms depending on the relationship between the individual or the organization that benefits from the favoritism. Regardless of their type, when considered at the organizational level, these privileges can cause usurpation of the rights of other employees, imbalance, injustice and unjustness among people; it can negatively affect the efficiency and effectiveness of the organization. In this context, the concept of favoritism has been first explained in the study; then, types of favoritism are discussed in two main groups as human favoritism and political favoritism. Although there are different classifications in the literature, human favoritism is handled as i- nepotism, ii- chronism, iii- tribalism and iv- compatriotism; political favoritism is handled i- patronage, ii- clientalism and iii- service favoritism within the scope of this study. Finally, the last 20 years' studies over the concept of favoritism are evaluated as content analysis, and the result obtained in the light of all these are evaluated in the study.