Four experiments were conducted in different parts of the State of São Paulo to study the effect of some green manure species on the yield of dry beans in the fall planting period. The green manures were sown in October and cut about three months later. Dry beans were sown between February 12 and March 4 of the following year. All the experimental plots received mineral fertilizer. In the average of the four experiments, the control plots produced 374 kilograms per hectare of air-dry beans. While the effect of Sorghum vulgarewas practically null and those of Dolichos lablabe, Tephrosia candidaand Cajanus cajanvaried fron +42 to +49%, that of Crotalaria junceareached +85%.