Political press conferences, while playing a significant role in international communication by heads of state and government, are still largely underexplored in interpreting studies. More scholarly attention is needed, particularly to examine the interpreter’s mediating role in these uniquely constrained communicative settings. Drawing on narrative theory and Wadensjö’s model of renditions, this paper investigates the interpreter’s mediating role at a 2011 joint press conference with the American and Chinese Presidents, at that time Barack Obama and Hu Jintao respectively. Specifically, the study examines how the interpretation comprises reduced, expanded and summarized renditions of the speakers’ narratives, and how the resulting mediation can affect not only their image, but also the outcome of the diplomatic communication between their respective countries. Here, the interpreter’s performance is subject not only to his language competence, but also to a number of other factors. On the one hand, his mediation can be facilitated rather than restricted by the constraints of the setting where the interpreting occurs, such as technical problems and time limitations. On the other hand, the mediation can also reflect the interpreter’s institutional role and the public narratives within the socio-cultural context. Keywords: interpreter mediation, political press conference, narrative theory, renditions