In translation, choosing appropriate equivalent is essential to convey the right message from ST to TT, and one of the issues that may have a determinative role in appropriate equivalent choice is the SP behavior of words and the relation existing between the SP of a word and semantic senses (i.e. negativity, positivity or neutrality) of its collocations in the context. This research explored the impact of Iranian translator trainees' semantic prosody knowledge on the appropriate selection of equivalents in translation. The probable influence of proficiency level or fields of study on the appropriate selection of equivalents with respect to SP was concentrated as well. The study showed if there is more than one equivalent of a word in another language, the knowledge of SP may help choosing the best one. Also, the results revealed that proficiency level and field of study among language learners can have an influence on choosing appropriate equivalents. The research indicated that the concept of semantic prosody should be included in the pedagogical schedule of translation training.