The constitution stands as the 1979 constitution as amended by the highest military ruling body known as the Provisional Ruling Council and it became operational on 29th May 1999. All the main features of the 1979 constitution are maintained by the 1999 constitution. It maintains the federal system of government in which powers of government are shared between the federal governments and the component 36 states.
The federal government possesses the exclusive Legislative list which contains 68 items which include: Defence, External Affairs, Custom and Excise Duties Insurance etc. The concurrent legislative list belongs to both the Federal and State legislative powers which include Industrail, Commercial or Agricultural Development, Education Allocation of Revenue, Achieves, Electricity, Collection of Taxes, etc. The concurrent legislative list has 30 items. In case of contradiction, the federal laws prevail over that of any state.
Th 1999 constitution also maintained the Executive President System of government in which the President is the Head of State, the Head of Government and the Commander-in-Chief of the Armed Forces. It provided for a clear separation of powers in which members of the Executive are not members of the legislature. Executive members are appointed by the President from outside the parliament on their merits though with the approval of the Senate and they are individually responsible to the President who has the power to remove any of them at will. The president is elected by the electorates and he is responsible to the electorates as well.
Under the 1999 constitution, the executive powers of a state shall be vested in the Governor of that state and may be exercised by him either directly or through the Deputy Governor and Commissioners of the government of that state or officers in the public service of the state, while the judicial powers of the Federation and the state are vested in the courts established for the Federation and the states and the Supreme Court of Nigeria remains the highest court of appeal for Nigeria.
The National Assembly also remains bicameral in nature with 109 members in the Senate (3 Senators per state, and 1 for Abuja), while the House of Representative as 360 members, each representing the 360 federal constituencies. On the other hand, the state legislature is unicameral. The state parliament is known as the State House of Assembly which shall consist of three or four times the number of seats which that state has in the House of Representatives divided in as way to reflect, as far as possible, nearly equal population, provided that a House of Assembly of a state shall consist of not less than 24 and not more than 40 members. The Senate shall be headed by a President and a Deputy President of the Senate, the House of Representatives by a Speaker and Deputy Speaker, while the State House of Assembly shall be led by a Speaker and a Deputy Speaker.
In the 1999 constitution, the Republic and the Judicial services are decentralized. It contains fundamental human rights, states and constitutional amendment procedures and impeachment clauses for the members of the executives. The long list of local government functions are also included in the constitution.