In business ethics research, little is known about why and how employees engage in unethical behavior, especially unethical pro-organizational behavior (UPB) and unethical pro-family behavior (UPFB). Based on cognitive-affective personality system theory and conservation of resources theory, this study aims to explore the mechanisms underlying the effects of workplace bullying, as a negative event, on UPB (Study 1) and UPFB (Study 2). In Study 1, workplace bullying negatively correlated with UPB where emotional exhaustion and organization-oriented moral disengagement played chain-mediating roles (...) in this relationship. In Study 2, workplace bullying positively correlated with UPFB where emotional exhaustion and family-oriented moral disengagement played chain-mediating roles in the relationship. In both studies, perceived forgiveness climate, as a conditional factor, was found to weaken the positive impact of workplace bullying on both emotional exhaustion and the chain-mediating effect of emotional exhaustion and moral disengagement in the relationship between workplace bullying and UPB/upfb. Overall, this study explains why, how, and when employees exhibit UPB and UPFB. The implications for theory and practices that could enable organizations to reduce employees’ unethical behavior are discussed. (shrink)