Action learning has travelled in some new directions and become an evolving practice since Revans first articulated his great idea. This paper focuses on some key challenges in the literature, some of which relate to these more recent directions in theory and practice. In particular, we consider the persistent problem of defining action learning and the varieties in practice which are in evidence, the nature of ‘action’ in action learning and the developing theory and practice of critical action learning as contrasted with the ‘classical’ approach to action learning. These debates are chosen for consideration here because they appear to strike at the heart of what action learning is for and because they are in evidence across a range of action learning literature. Some implications of these debates for human resource development (HRD) are also considered, including the potential action learning has for making a contribution to organizational learning, especially in treating ‘wicked’ problems and ill-structured challenges.