This paper discusses and comprehensively evaluates a mentoring scheme for junior female academics. The program aimed to address the under-representation of women in senior positions by increasing participation in networks and improving women's research performance. A multifaceted, longitudinal design, including a control group, was used to evaluate the success of mentoring in terms of the benefits for the women and for the university. The results indicate mentoring was very beneficial, showing that mentees were more likely to stay in the university, received more grant income and higher level of promotion, and had better perceptions of themselves as academics compared with non-mentored female academics. This indicates that not only do women themselves benefit from mentoring but that universities can confidently implement well-designed initiatives, knowing that they will receive a significant return on investment. (Contains 1 table and 5 figures.)