Bicameral legislatures have recently attracted considerable attention in comparative literature. However, this increased interest has been uneven and insufficient to close the many gaps existing in this area of research. Latin America, a continent with a long tradition of bicameralism, has been all but ignored. This study develops a system of scores with which to measure the strength of the bicameral systems of the Americas. Twelve cases are examined: the nine current bicameral legislatures, two unicameral cases that became in the 1990s and, finally, the United States, which provides a pattern of comparison and is the model on which Latin American constitutions have been based.