This chapter evaluates the specific advantages and disadvantages of different seed systems for small-scale farmers. Seed Sovereignty, as a component of food sovereignty, could be conceptualized as the right of people to define their own seed systems. While concepts of sovereignty have traditionally pertained to the nation state, when used in food sovereignty and the right-to-food movements, the focus is on the right of the people to decide. Farmers are the primary users of seed and are directly dependent on seed for their livelihoods. For some farmers, particularly small-scale farmers, seeds also directly impact on their food security and nutrition, and have cultural or spiritual value that cannot be commoditized. The chapter describes the breeding, production, distribution and quality assurance of seeds, and their implications on the access and appropriateness of current seed systems for small-scale farmers. Complementing on-farm seed sourcing, informal markets is an important source of seed for small-scale farmers, particularly during years when crop production is low.