Purpose: This study aims to describe the design of a provincial government ministry group mentoring program and examine mentees' and mentors' experiences in the program. Design/methodology/approach: A total of 151 mentees rated their satisfaction in a post-program survey. The survey was followed by in-depth, semi-structured interviews with 10 mentees and 11 mentors. Findings: In all, 87 per cent of mentees rated their learning as effective. Benefits to mentees were relevance of the learning, and senior leader/mentors use of current issues, events and personal stories. Delivery through a combination of Web conferencing and collaboration technologies was most effective. Mentors learned from mentees and other mentors. Regular and full mentee participation was an identified issue. In addition, not all mentoring teams worked well together. Research limitations/implications: The selection criteria favored participants who had a positive experience. Including more participants who were disengaged or less active may have revealed what inhibited full engagement. Complex underlying systemic and cultural issues negatively affected mentee participation and mentoring team effectiveness. It is unclear whether this was caused by intrinsic or extrinsic barriers. Further study could shed light on how to address participation issues. Practical implications: Selection criteria favored highly active participants who had a positive experience. Including more disengaged or less active participants may have revealed barriers to full engagement. Social implications: Despite a context of extreme organizational churn, this program delivered cost-effective and engaging learning to a large number of employees. Recommendations are made to further strengthen the program. Originality/value: This contextually grounded case study will be useful to those who plan to implement a group mentoring program.