This report presents the results of the research phase of the Biodiversity for Opportunities, Livelihoods and Development (BOLD) project, a ten-year initiative (2021-2030) funded by the Government of Norway and coordinated by the Global Crop Diversity Trust. The research aimed to analyze the functioning of seed systems in Tanzania and identify strategies for improving smallholder farmers’ access to and use of crop diversity. The study offers a comprehensive overview of Tanzania’s seed system by analyzing its primary components: variety development and management, seed production, seed dissemination, and seed governance. It examines the formal, national-level processes in place for the development, release, production and quality assurance of new varieties, as well as seed distribution.