The aim of this study is to examine the impact of AMO-HR Systems (i.e., ability-enhancing HR practices, motivation-enhancing HR practices and opportunity-enhancing HR practices) on proactive employee behavior through the effect of leader-member and team-member exchange. A questionnaire was developed based on prior related works to collect the required data from a sample of 230 employees from 13 small companies in the service industry in the Jordanian capital, Amman. The results showed that nine HR practices are significant predictors of employee proactivity behavior. The impact was significantly mediated by leader-member and team-member exchange. On the ground of the results, the study concluded that proactivity is a function of three categories of HR practices. First, an employee should be supported to enhance his or her ability. Second, an employee should be motivated and granted the opportunity to share knowledge. Third, employees should be encouraged to participate in problem solving, in the presence of leader-member coordination, to improve relationship quality and team-member recognition, support, and effective communications. Accordingly, recommendations, social and managerial implications were reported.