PurposeAdopting a followership perspective and drawing upon the literature on perceived support, we provide new theoretical insights into when and why supervisors engage in unethical behavior with the intention of benefiting a “favorite” follower, referred to as unethical favoritism behavior (UFB).Design/methodology/approachWe conducted two studies: an experiment and a multi-rater field study. Data were collected and analyzed using AMOS and the Macro process for SPSS.FindingsWe found that a follower’s standing among his or her peers in terms of citizenship behaviors toward their supervisor (i.e. relative organizational citizenship behaviors toward supervisor or ROCBS) has a positive effect on the supervisor’s perception of the follower’s support. The results further reveal that the choice of the supervisor on whether to reciprocate or not the perceived support (triggered by ROCBS) with UFB depends on the supervisor’s competence uncertainty (i.e. the degree of supervisor uncertainty regarding his/her work competencies).Originality/valueOur findings broaden the way the supervisor–follower relationship has traditionally been investigated in the organizational behavior literature by showing that under certain circumstances, followers’ good behaviors might become an antecedent to supervisors’ unethical acts.