The political party of outgoing President Jose Mujica, who gained international notice for social reforms such as legalisation of marijuana and gay marriage, leads going into Sunday's election to replace him but victory is far from assured.
Vazquez is going to be president again because Uruguayans don't want to return to the past.
Polls suggest that neither of the parties of the top two presidential candidates will obtain the 50 percent needed to avoid a second round on the 30th of November.
The competing parties are Mujica's left-leaning Broad Front and the center-right National Party.
Uruguay's constitution bars a president from holding two consecutive terms in office so Tabare Vazquez returned to be the Broad Front's candidate.
Vazquez, the Broad Front's 74-year-old presidential candidate, was president of Uruguay in 2005-2010. His top challenger, 41-year-old National Party candidate Luis Alberto Lacalle Pou, is the son of a former president.
"Vazquez is going to be president again because Uruguayans don't want to return to the past," said Analia Vernini, a 36-year-old dentist.
The latest opinion polls show Vazquez with the support of 43 percent of voters compared with 31 percent for Lacalle Pou.
The Uruguayan law barred Mujica from running for another term, even though he remains popular after leading Uruguay during a period that saw the economy grow and wages rise.
Demanding new ideas
But critics say his government failed to deal with problems in education, security and environmental protection.
"A part of society has changed its mood and seems to be demanding new ideas from the political leadership,'' said Daniel Chasquetti, a political scientist at Universidad de la Republica in the capital.
While recognising Mujica's achievements in the economic realm, Pou campaigns on a promise to focus on crime and education.
Pou also said that he would seek to modify the law that Mujica spearheaded to create the world's first national marketplace for legal marijuana.
Voters will also elect lawmakers on Sunday. Neither the Broad Front nor Lacalle Pou's National Party are likely to win a majority in Congress, meaning the next president will face a tougher time than Mujica in passing laws.
Uruguayans will also vote in a referendum on whether to reform the constitution to lower the age a person can be criminally charged as an adult from 18 to 16.