The objective of seed conservation is to preserve the genetic integrity of the seed under controlled conditions. For this, representative seed samples of the natural populations are stored, i.e., the gene frequency of the sample must be equal to that of the original population. The storage conditions should be such that the seed should be kept viable for the longest possible time. This chapter deals on how to store seeds of crops and wild plant species for medium- and long-term conservation because seed conservation in gene banks remains the most efficient method for conserving plant germplasm of the cultigen and their wild relatives. The arrangements taken for preserving seeds are given herein considering particularly at what happens at various gene banks elsewhere. The focus of this chapter is seed conservation in gene banks.