While research on ‘authenticity at work’ is gaining scholarly attention, the understanding on how authenticity at work shapes dark interpersonal outcomes such as interpersonal deviance still is at nascent stage. Building on self-determination theory, we posit that the relationship between authenticity at work and interpersonal deviance is mediated through dual pathways of work passion. Moreover, we identify network support and promotion focus as a boundary condition to the effects of both forms of work passion on interpersonal deviance. Two wave data collected from employees and their supervisors supports the mediation effects for the dual pathways of work passion including harmonious work passion and obsessive work passion. High network support and low level of promotion focus exacerbates the negative effects of harmonious work passion while the effects of obsessive work passion remained unmoderated. Overall, we broaden the impact of authenticity at work on dark interpersonal behaviors.