The vote is the second after power changed hands in the 2000 elections which brought to an end 40 years of rule by the Socialist Party, in a country lauded for its peace and stability in an otherwise troubled region.
Seen as a symbol of change in Senegal after breaking four decades of socialist rule in the former French colony, Wade faces a number of rivals, including a former prime minister he sacked two years ago.
Idrissa Seck, 47, was once considered the obvious successor to Wade before falling out of favour and being imprisoned by Wade for seven months.
Other leading contenders are the 60-year-old Ousmane Tanor Dieng, a socialist of the former ruling party, and the dissident Moustapha Niasse, 68, an ex-prime minister who served in the governments of both Wade and his socialist predecessor Abdou Diouf.
Campaigning for the polls finished early on Friday, with authorities banning all rallies, TV adverts and all other forms of electioneering in the final days before the vote.
Campaigning, which was generally peaceful ended on a violent note after rival supporters clashed in Dakar.
The skirmishes, pitting Wade loyalists against supporters of former prime minister Seck, injured at least 10 people, causing concern after an otherwise colourful but calm election campaign.
Legislative elections, which were to have taken place at the same time as the presidential vote, have been postponed to June.