This book provides basic knowledge on how to produce, multiply and use propagation material in seed potato production and supply systems world wide. Healthy, vigorous seed tubers are essential in potato production. Producing them used to be expensive and difficult. Multiplication rates in the field are low, seed-borne diseases are numerous and seed tubers lose quality during storage between growing seasons. Recently, novel methods of multiplication have revolutionised the seed potato industry. This has resulted in a diversity of seed production systems adjusted to the local potential and needs.