This paper examines the emotions that eight teachers experienced during intervention research project on the transformation of their teaching practices. During the program which we designed, the teachers were trained to transform their teaching practices so that they would include more features of dialogic education. In this paper, we analyze data from repeated interviews with teachers who participated in our project. Based on qualitative analysis of our data, we differentiated among four groups of teachers, each with a unique self-understanding. The groups included teachers who were: perfect, eager to learn, in a good mood, and uncertain. Our paper shows that each group experienced specific emotions during the program. The only group that did not experience negative emotions was teachers in a good mood. These teachers also implemented the fewest changes in their teaching practices. Our results thus show that a lack of negative emotions limited the efficacy of teacher development.