This article explores the issue of quality in online career mentoring. It builds on a previous evaluation of Brightside, an online mentoring system in the UK which is primarily aimed at supporting young people's transitions to further learning. The article notes that participants in Brightside's mentoring programmes reported satisfaction with their experiences, with many stating that it helped them to make decisions and to positively change their learning and career behaviours. However, the article argues that there are challenges in ensuring quality and consistency connected to both the voluntary nature of mentoring and the online mode. The article proposes a 10-point quality framework to support quality assurance, initial training and professional development for online mentors.