The impact of emotions on professional identity development in the field of second language teacher education has become a focus of research quite recently. In many French teacher-training contexts the construction of a mainly rational professional identity has been thought relevant, emotions such as fear, anger or sadness being very often considered as a nuisance. Paradoxically, pre-service teachers continue to stress the emotional aspects of their work without really being heard by the educational authorities who keep emphasizing linguistic and didactic proficiency. This chapter addresses both the negative and positive impacts of emotions on the construction of second language teachers’ professional identity at the start of their career and proposes concrete ideas for pre-service and in-service training. After presenting a theoretical and conceptual framework (Plutchik in Emotion a psycho-evolutionary synthesis. Harper, New York, 1980; Psychological Review, 99(3), Jul 1992, 550–555, 1992; Belzung in Biologie des émotions. de Boeck, Louvain-la-Neuve, 2007; Jonczyk in Affect-language interactions in native and non-native English speakers. Springer, 2016) and a literature review about emotions, the authors analyse logs kept by seven pre-service teachers over a school term and comment on the results of a survey they conducted on four groups of teachers at different stages of their teaching career. They conclude by suggesting some concrete ways to empower language teachers as they build a well-balanced professional identity. Keywords