Under Nigeria's federal constitution, the president and 36 state governors are elected directly to a four-year term, for a maximum of two terms.
There are 24 parties offering candidates for president and almost 50 parties in total. The three largest parties are: People's Democratic Party, All Nigeria People's Party and Action Congress.
April 14 - Election of governors for 36 states and members of state houses of assembly.
April 21 - Election of president and members of the National Assembly, comprising 109 senators and 360 members of the House of Representatives.
May 29 - Olusegun Obasanjo, current president who has already served two terms, hands over to his successor.