Mentoring is a tool that has the potential to help women entrepreneurs grow their businesses, and in some cases change their lives. Models of mentoring are more widely available than ever before. Modern approaches emphasize that women benefit from a wide array of mentors—not only experienced and successful women, but also male role models, peers, and even competitors. Mentoring is also increasingly conducted through dynamic platforms, often online or through social media, and is increasingly integrated as part of broader programs.This week, the Multilateral Investment Fund launched a mentoring challenge to identify innovative mentoring models being applied in the industry. So we thought it would be a good time to reflect on what we know about how mentoring can be most helpful for women entrepreneurs, and how some of the most promising models can be scaled up.