A significant amount of U.S. farmland, in terms of both acreage and total, market value, is rented. There is wide variation, however, depending on farm size and type of enterprise. Reliance on leasing increases with size of operation. Compared with owned land, a higher percentage of all rented farmland is in the larger farms. Tenure patterns vary considerably by type of farm, with leasing being most important in cash grain enterprises. These relationships suggest that if the trend toward increasing farm size continues, an even higher percentage of all rented land will be in the larger farms. This implies greater reliance on part-owner operations, particularly among farming operations that require large acreages. Estimates are based on the 1969 Census of Agriculture and pertain chiefly to farms with gross annual receipts of $2,500 or more.