Zambia became a republic immediately upon attaining independence in October 1964. The constitution promulgated on August 25, 1973, abrogated the original 1964 constitution. The new constitution and the national elections that followed in December 1973 were the final steps in achieving what was called a "one-party participatory democracy."

The 1973 constitution provided for a strong president and a unicameral National Assembly. National policy was formulated by the Central Committee of the United National Independence Party (UNIP), the sole legal party in Zambia. The cabinet executed the central committee's policy.

In accordance with the intention to formalize UNIP supremacy in the new system, the constitution stipulated that the sole candidate in elections for the office of president was the person selected to be the president of UNIP by the party's general conference. The second-ranking person in the Zambian hierarchy was UNIP's secretary general.

In December 1990, at the end of a tumultuous year that included riots in the capital and a coup attempt, President Kaunda signed legislation ending UNIP's monopoly on power. In response to growing popular demand for multi-party democracy, and after lengthy, difficult negotiations between the Kaunda government and opposition groups, Zambia enacted a new constitution in August 1991. The constitution enlarged the National Assembly from 136 members to a maximum of 158 members, established an electoral commission, and allowed for more than one presidential candidate who no longer had to be a member of UNIP. The constitution was amended again in 1996 to set new limits on the presidency (including a retroactive two-term limit, and a requirement that both parents of a candidate be Zambian-born). The National Assembly is comprised of 150 directly elected members, up to eight presidentially appointed members, and a speaker. Zambia is divided into nine provinces, each administered by an appointed deputy minister who essentially performs the duties of a governor.

The Supreme Court is the highest court and the court of appeal; below it are the high court,magistrate's court, and local courts.

Zambia maintains an embassy in the United States at 2419 Massachusetts Avenue, NW, Washington, DC 20008 (tel. 202-265-9717/8/9).