The article presents two studies examining the impact of formal interpreting training (FIT) on Working Memory Capacity (WMC) of student-interpreters. In Study 1, we compared the storage and processing WMCs of last-year student-interpreters with the storage and processing WMCs of first-year student-interpreters and last-year Foreign Language Education (FLE) students. In Study 2, we examined the impact of FIT on the WMC of students interpreters via comparing their results on the WM tasks at the beginning and at the end of their FIT. In both studies, Digit Span Task (DST) and Reading Span Task (RST) were utilized to test storage and processing WMCs. The results of Study 1 revealed that the last-year student-interpreters performed better than the first-year students interpreters and the last year FLE students on the RST, but not on the DST. The findings of Study 2 were consistent with Study 1 showing that after FIT, the student-interpreters performed better on the RST but not on the DST. Our findings can be considered as evidence supporting the view that FIT had a beneficial effect not only on the interpreting skills of student interpreters but also on the central executive and processing capacity of their WM. (C) 2018 Elsevier B.V. All rights reserved.