In this article, the authors develop a perspective on the value of, and methodologies for, comparative planning research. Through comparative research, similarities and differences between planning cases and experiences can be disentangled. This opens up possibilities for learning across planning systems, and possibly even the transfer of best planning and policy practices across systems, places, or countries. Learning in governance systems is always constrained; learning in planning systems is further constrained by the characteristics of the wider governance system in which planning is embedded. Moreover, self-transformation of planning systems always takes place, not always driven by intentional learning activities of individuals and organizations, or of the system as a whole. One can strive to increase the reflexivity in planning systems though, so that the system becomes more aware of its own features, driving forces, and modes of self-transformation. This can, in turn, increase the space for intentional learning. One important source of such learning is the comparison of systems at different scales and learning from successes and failures. We place this comparative learning in the context of other forms of learning and argue that there is always space for comparative learning, despite the rigidities that characterize planning and governance. Dialectical learning is presented as the pinnacle of governance learning, into which comparative learning, as well as other forms of learning, feed.