The purpose of this study was to demonstrate the effectiveness of a Bilingual Mentors Program to develop cognitive, non-cognitive or second language skills on senior and freshmen university students, respectively, from two different Degrees at the University of Granada (Spain). Two Degrees were involved in this project, English Studies provided student mentors and Primary Education Teacher Training provided mentees. The procedure consisted of the following steps: (a) a collaboration agreement between institutional staff responsible for both Degrees was reached, (b) a sampling process was designed and implemented, (c) measurement instruments were built and selected, (d) mentors training for two 90 minutes sessions took place, and finally, (e) the program intervention itself consisted of 10 90-minute mentoring sessions delivered during one semester. The results show significant size effects for most of the dependent variables analyzed for mentors and perceived benefits on second language command for mentees.