This chapter focuses on comparative human resource management (HRM). It explores the differences between nations in the way that they manage their human resources. Within a context of increasing globalisation, the chapter highlights how context matters to HRM. Fundamental to understanding these differences between countries are two concepts: the notions of cultural and institutional differences, and the notions of convergence and divergence. The chapter contributes to a better understanding of the main concepts and theories relevant to comparative HRM. First, this chapter shows that cultural and institutional explanations are valuable to the comparative HRM approach. Further, it argues that convergence of trends is apparent, but final convergence remains unrealistic. Finally, it outlines some of the key theoretical, empirical and practical challenges posed by a comparative approach to HRM.