This study was concerned with examining the economic factors of organizing marketing and supply cooperatives by low-income farmers in South Carolina. Managers of four low-income farmers' cooperatives, a sample of 98 members of these cooperatives and 93 nonmember farmers were interviewed to ascertain the data for this study. It was observed that returns were less than cost for these four cooperatives in 1972. A low volume of business with high selling and administrative costs was given as the primary reason. Losses were small when sales were made to processing markets on a contract basis and high when consignment sales were made to the fresh market. Farm supply operations made small but positive contributions to net profits. The members of the cooperatives suggested that the cooperatives should improve the management and engage in the buying and selling of larger varieties of products. The nonmember low-income farmers indicated that they will become members when the management of the cooperatives is improved and when the advantages of membership are clearly shown. Low-income farmers find it convenient to produce vegetable crops. The most important crops are tomatoes and cucumbers. Model tomato and cucumber packinghouses of various capacities were examined. Although the potential membership was found to be high, the potential volume of business was relatively small. The initial investment was high. Low-income farmers' cooperatives must be able to attract other medium income farmers into the cooperatives to assure success in the long run.