Abstract The main objective of this research was to determine the effect of preferential treatments in the workplace as an independent variable and perceived fairness of employees as a mediating variable on the Employees' innovative work behavior. And based on the data obtained from the questionnaire that was distributed to all staff of the research and development department in the registered pharmaceutical companies that were Central Agency for Public Mobilization and Statistics, where the total number of workers in the R&D department in those companies was (537) workers, so the response rate was (418) valid form as 77.8%. And through the use of the method of Partial Least Squares (PLS). The results of this study confirmed the research hypothesis concerning the mediation of perceived fairness on the relationship between preferential treatments at workplace and employee Innovative work behavior. Also, according to the results, those findings indicate that perceived fairness had a direct effect on Innovative work behavior. Implications for management and future research are discussed. Keywords: Perceived fairness, Innovative work behavior, Idea generation, Idea connection, Implementation starting activities, Involving others, Innovation outcomes, preferential treatments, favoritism, nepotism