This M.A. thesis focuses on the relationship between theatre classes, affective factor, and speaking skills. The main goal of the thesis is to explore the potential positive effects of theatre on the development of students’ speaking skills. In the theoretical part, the focus is on the affective factor's role in the foreign language classroom and its influence on the development of the competence that the negative affective factors influence the most, i.e. oral communication skills. It shortly comments on the current situation concerning theatre use in Slovenian schools. Moreover, it explores the possible advantages and disadvantages of theatre use in class, and briefly presents some useful guidelines regarding the choice of play. The empirical part consists of the analysis of semi-structured interviews with two groups of university students that participated in a theatre class. One group consisted of the students of English who took part in the English theatre club, and the other one of the students of Spanish who were involved in the Spanish theatre class. Through the analysis of the interviewees' personal experience with theatre, this research examines the following facets of theatre use in the classes of foreign languages: the relationship between participation in a theatre class and the level of the affective filter, the link between participation in a theatre class and language acquisition, and the relevance of student participation in a theatre class to their engagement in other classes. The research results show a positive impact of theatre use on students' speaking skills. Participation in a theatre class/club helped lower the students' affective filter and aided students in improving their knowledge of a language. Theatre classes also had a positive effect on students' active engagement in other courses.