The prime minister has always maintained the 2008 election was rigged. At the time, the electoral commission said Tsvangirai and party had won, but not by enough to avoid a runoff. He later withdrew from the runoff, saying government loyalists had killed hundreds of his supporters.
Citizens say this year's election is crucial in more ways than one. Despite the setbacks, it provides another shot at democracy.
"We are still a young country ... our democracy is still young," said Nigel Mugamu, who lives in the Zimbabwean capital of Harare. "A lot of African countries have changed leadership at least once or twice. We haven't seen a new face. From that perspective, it's an exciting time. Will this be the moment it will happen?"
Hope after hyperinflation
Mugamu said a peaceful election will help boost investment. This is the first poll since Zimbabwe battled hyperinflation that left investors jittery and led many to abandon the country's currency.
In 2009, the nation introduced a 100 trillion-dollar bill that was worth about $300 in U.S. currency. At the time, a loaf of bread cost about 300 billion Zimbabwean dollars.
The hyperinflation forced traders to insist on international currency to hedge against losses. They preferred the U.S. dollar or South African rand, and most workers demanded their salaries in foreign currency.
Despite widespread poverty, the nation has made major strides since then, experts say.
"Zimbabwe has made considerable progress in stabilizing the economy since the end of hyperinflation in 2009," the International Monetary Fund said last month.
Since then, the nation's gross domestic product "has grown by an average of over 7% and inflation has remained in the low single digits. Government revenues have more than doubled from 16% of GDP in 2009 to an estimated 36% of GDP in 2012, allowing the restoration of basic public services."
And as the nation returns from the brink of a crippled economy, Zimbabweans are hopeful.
Linda Mukusha braved long lines and chilly morning weather to cast her vote in Harare.
"I hope Zimbabweans turn out to vote in huge numbers," she said. "Whoever wins, the country needs to move forward."
She proudly displayed her inked finger to show she had cast her ballot