The aim of this Masters’ thesis was to observe the influence of context on simultaneous interpreting. Therefore, a study was conducted, in which 15 student interpreters of the Spanish, French and Italian booths were asked to interpret two speeches. While the interpreters were familiar with the context of one of the speeches, they were not familiar with the context of the other one. The aim of this experiment was to find out whether time lag was shorter in the interpretations of the speech with the familiar context than in the interpretations of the one with the less familiar context. The results showed that contextual knowledge aids in keeping a shorter time lag and that contextual knowledge helps in reducing errors. However, participants did not produce a word in the target language before hearing the same word in the source language speech, so I cannot conclude that prediction took place.