This article deals with the training of interpreters and the effects of such training in the workplace. It is the intention, on the one hand, to analyse the interpreter’s intervention after some specific training, and on the other hand, to check the effectiveness of the interpreters’ training in the workplace when these students are acting as interpreters in real situations. In other words, to investigate how theory can be integrated into practice through research. The data come from two main sources: the analysis of simulated role plays in health care setting as part of the training program for interpreters and translators in public services at the University of Alcalá, Madrid (UAH), and comments by the students in the workplace when acting as interpreters in hospitals and healthcare centres as part of their internship.