Bolivia is a unitary state consisting of nine departments (Spanish: departamentos). Departments are the primary subdivisions of Bolivia, and possess certain rights under the Constitution of Bolivia. Each department is represented in the Plurinational Legislative Assembly—a bicameral legislature consisting of the Senate and the Chamber of Deputies. Each department is represented by four Senators, while Deputies are awarded to each department in proportion to their total population.
Out of the nine departments, La Paz was originally the most populous, with 2,706,351 inhabitants as of 2012 but the far eastern department of Santa Cruz has since surpassed it by 2020; Santa Cruz also claims the title as the largest, encompassing 370,621 square kilometres (143,098 sq mi). Pando is the least populated, with a population of 110,436. The smallest in area is Tarija, encompassing 37,623 square kilometres (14,526 sq mi).