The purpose of this paper is to offer some theoretical as well as empirical examples that describe the interrelations between pedagogical content knowledge (PCK) and emotional knowledge in teaching and learning. The argument put forward is that there is a need to expand current conceptions of PCK and acknowledge the role of emotional knowledge. It is shown how a teacher's emotional knowledge about teaching and learning is an inextricable part of the ecosystem of teacher knowledge; this is called "emotional ecology." Our research shows that the construct of emotional ecology occurs on different planes as there are different types of emotional knowledge that are aspects of PCK. The implications for pre-service and in-service teacher development are discussed.