Recently, scholars in the field of strategic human resource management (SHRM) have shown a growing interest in the critical role of line managers in delivering human resource (HR) management practices. However, the current focus on line managers’ individual characteristics (e.g., abilities and motivation) as antecedents of their HR implementation behaviors neglects the broader organizational context in which they are situated. I draw on insights from social learning and social information processing research to demonstrate how HR implementation behaviors of line managers’ supervisors can flow down the organizational hierarchy, having “trickle-down effects.” Next, I examine how HR implementation behaviors of line managers’ peers can spill over within the organizational hierarchy to produce “trickle-around effects.” Finally, focusing on the differences between the mechanisms of trickle-down effects (social learning from others at higher hierarchical levels) and trickle-around effects (social learning from others in the same positions), I demonstrate how these effects interact to predict the HR implementation behaviors of focal line managers.