It is only recently that cognitive psychologists have shown interest in the processes involved in translation and interpretation. In many cases this interest arises from the special difficulty that these tasks impose upon the processes of comprehension and speech production. For example, in simultaneous interpreting, these processes have to be performed concurrently, in different linguistic codes and under strong temporal pressure. This paper focuses on the processes of comprehension in simultaneous interpreting. It explores whether the comprehension processes involved in interpreting are different in nature from those involved in normal reading or listening and if so, how. Also, an important question in the experiments was to determine whether the interpreters’ training and experience had an effect over and above the possible effects of knowledge and use of two languages.