Though interpreters and professional associations agree that seeing the speaker improves simultaneous interpreting performance, empirical evidence supporting this assumption is lacking. This thesis explores the effect of visual input on simultaneous interpreting accuracy through an experiment and questionnaire. 16 first- and second-year student interpreters worked on two speeches, one with and one without visual input, and commented on its utility. Each rendition was checked for omissions, substitutions, and additions to determine the overall error score. Although a trend towards improved accuracy with visual input emerged, the results lacked statistical significance, possibly due to the small sample. Participants were split on the utility of the visual input. On average, second-year students benefited more from and felt more comfortable with visual input than first-year students, suggesting that more interpreting practice improves the integration of auditory and visual input. Further research is needed to validate existing assumptions on the effect of visual input.