All agricultural production whether of crops, trees, forages, livestock, or fish starts with seeds,* making seed security vital to food security. Seed security means that producers smallholder farmers especially have permanent and unrestricted access to adequate quantities of quality seed that is suitable to their agroecological conditions and socioeconomic needs. Efforts to enhance seed security should be inclusive, without disparities related to income, social class, age, or gender. Yet, gender gaps reveal themselves across the seed system, including in the breeding, production, selection, and distribution stages, as well as in how the seeds are used and who reaps the benefits from this use. While there is extensive literature on seed systems and how they should be organized to ensure seed security for smallholder farmers, a body of research unpacking gender dynamics within these systems has just begun to emerge. This includes a portfolio of projects initiated and funded by the CGIAR Collaborative Platform for Gender Research, which was hosted within Gender Research and Coordination from 2017 2019 (Box 1). This brief summarizes this early work and provides an outlook for future research to mainstream gender analysis in seed systems development. PIM SYNTHESIS BRIEF NOVEMBER 2020 KEY MESSAGES To enhance the reach and effectiveness of formal breeding programs, formal seed systems must generate quality seeds that respond to the different needs and preferences of both women and men, across socioeconomic categories.