The purpose of this study was designing and testing a model of some antecedents and outcomes of workplace envy. The participants of the study were 304 employees of NISOC in Ahvaz (215 male and 74 females) that were selected by stratified random sampling method. The instruments used in this study were workplace envy, leader-member exchange (LMX), core self-evaluation (CSE) pro-social behavior, social undermining, and moral disengagement questionnaires. The fitness of the proposed model was examined through structural equation modeling (SEM) using SPSS-23 and AMOS-23 software packages. The indirect effects were tested using the bootstrap procedure in Preacher and Hayes (2008) SPSS Macro program. Findings indicated that the proposed model fits the data and all hypotheses were confirmed. The effect of leader-member exchange (LMX) and core self-evaluation (CSE) on workplace envy and the effect of workplace envy on pro-social behavior, social undermining, and moral disengagement were significant. Moral disengagement also mediated the relationship between workplace envy and social undermining.