Purpose – The purpose of this paper is to understand the dilemmas facing Hong Kong vice-principals in discharging their roles and to further explore their engagement in informal mentoring as a coping mechanism in the absence of a structured professional development program. Design/methodology/approach – The qualitative study was conducted in the form of in-depth face-to-face, loosely structured individual interviews with ten informants from a variety of personal and school backgrounds, contributing to a set of data that unveiled the basic themes. Findings – Three dilemmas facing Hong Kong vice-principals were identified: juggling administrative work with teaching, standing by management or siding with peer teachers, and forced innovation vs omnipresent conservatism. The findings also suggested that the informants tended toward external resources intentionally with a view to gaining emotional support as well as professional stimulation. They also engaged in informal mentoring, which took the form of observing principals’ behaviors, joining support groups organized by school governing bodies, and enrolling in academic programs offered by universities and/or professional bodies, as a way to resolve the dilemmas. Research limitations/implications – Informal mentoring has been identified as an effective approach for Hong Kong vice-principals to acquire the skills and knowledge needed to overcome workplace challenges and the feelings of loneliness experienced upon changing their role. The findings point to the importance of formalizing mentoring in vice-principal development programs. Originality/value – This study is the first of its kind to explore the impact of informal mentoring on vice-principals in Hong Kong where both dual-career track systems and a structured mentoring programs are missing. Copyright © 2016 Emerald Group Publishing Limited.