Government
Type: Republic within the Commonwealth.
Independence: May 26, 1966; Republic, February 23, 1970.
Constitution: 1980
Branches: Executive--executive president (chief of state and head of government), prime minister. Legislative--unicameral National Assembly of 65 deputies. The ten administrative regions of the country elect 25 members, 40 are elected from party lists by proportion of the national vote. Judicial--Judicial Court of Appeal, High Court.
Subdivisions: 10 regions.
Political parties (voting seats in the National Assembly): People’s Progressive Party/Civic (PPP/C) 34; People’s National Congress (PNC) 27; Guyana Action Party/Working People's Alliance (GAP/WPA) 2; Rise Organize and Rebuild (ROAR) 1; and The United Force (TUF) 1. Total seats: 65. Elections held March 19, 2001.
Suffrage: Universal at 18.

Government of Guyana
Legislative power rests in a unicameral National Assembly, with 40 members chosen on the basis of proportional representation from national lists named by the political parties. An additional 25 members are elected by regional administrative districts. The president may dissolve the assembly and call new elections at any time, but no later than 5 years from its first sitting.

Executive authority is exercised by the president, who appoints and supervises the prime minister and other ministers. The president is not directly elected; each party presenting a slate of candidates for the assembly must designate in advance a leader who will become president if that party receives the largest number of votes. Any dissolution of the assembly and election of a new assembly can lead to a change in the assembly majority and consequently a change in the presidency. Most Cabinet ministers must be Members of the National Assembly; the Constitution limits non-Member “technocrat” ministers to five. In practice, most other ministers also are members. Technocrat ministers serve as non-elected members, which permits them to debate but not to vote.

The highest judicial body is the Court of Appeal, headed by a chancellor of the judiciary. The second level is the High Court, presided over by a chief justice. The chancellor and the chief justice are appointed by the president.

For administrative purposes, Guyana is divided into 10 regions, each headed by a chairman who presides over a regional democratic council. Local communities are administered by village or city councils.
source: http://www.state.gov