Concerns about poor L1 reading skills in undergraduate students have been expressed in several contexts. These skills form a basis for building robust L2 reading comprehension skills, vital for translators. This study, which is part of a larger organization-based action research study to improve L1 reading levels, aimed to explore how L1 reading comprehension skills were reflected and predicted the overall academic performance of students on a South American undergraduate translator training programme using regression modelling. Seventy-nine students from second, third and fourth year of the programme were recruited for this study. They were asked to take a standardized Spanish reading comprehension test measuring word-level comprehension, sentence-level comprehension and text-level comprehension. Also, participants' final grades for all completed courses were obtained, as well as students' scores in a pre-entry English test providing a baseline level L2 knowledge prior to being formally trained on English. The results showed that students' overall grades were predicted by and correlated with lower order sentence-level reading skills, rather than higher-order text-level skills, which was found to be of some concern inasmuch as the translation process demands reading skills that go well beyond the sentence boundary. Given the impact that evaluation can have on student learning, and that the connection between reading comprehension and academic results on translation programs does not appear to have been considered in the literature previously, the study may highlight a need for other institutions wishing to improve L1 reading skills to similarly examine their summative evaluation practices.