This study investigates the effect of explicit teaching of segmentals vs. prosody on the quality of interpreting by Farsi-to-English interpreter trainees. Participants were native speakers of Farsi and BA students of English translation and interpreting in Iran, who were assigned to one of three groups. No differences in English language skills were found between the groups prior to the experiment. The control group listened to and discussed English audio and video recordings and did exercises in consecutive interpreting. One experimental group instead spent part of the time on explanation of, and exercises with, English prosody. The second experimental group spent part of the time on explanation of, and exercises with, English segmentals. Total instruction time was 12 hours for each group. The students' performance in consecutive interpreting was then rated independently by three experts. Results showed that both experimental groups performed better than the control group. Moreover, teaching prosody had a larger positive effect on the overall quality of interpreting from Farsi into English than segmental instruction. We argue that the interpreting curriculum can be strengthened by devoting a small portion of the time to explicit instruction on segmental and (especially) prosodic differences between source and target language.