The UN, after presidential polls were held peacefully over two rounds in March and April, says it will pull out its remaining 1300 troops within six months if the general election tomorrow goes well.
There are concerns that violence will reignite in the oil-rich but underdeveloped state if none of the 21 parties wins an outright majority and a fragile coalition takes power.
Following the end of Portuguese rule in 1975, East Timor was occupied by Indonesia for 24 years. About 183,000 people died from fighting, disease and starvation before the half-island state voted for independence in 1999.
The country has offshore fields of oil and natural gas. Its Petroleum Fund has swelled to $US10 billion ($A9.72 billion), but corruption is common and half its 1.1 million people are classified as living in poverty.
In the elections, the left-wing Fretilin party, which became synonymous with the pro-independence struggle, has a populist platform for spending the oil money to lift income and education levels.
The centre-left National Congress for Timorese Reconstruction (CNRT) wants instead to establish a plan for longer-term investment on major infrastructure projects.
Tomorrow's polls are due to be the last big test before East Timor, which in May celebrated a decade of formal independence, takes full responsibility for its own security.
The United Nations Integrated Mission in Timor-Leste (UNMIT) was deployed in 2006 after a political crisis.
The only major violence since then was a failed assassination attempt in 2008 on president Jose Ramos-Horta, who lost to Taur Matan Ruak in the recent presidential election. SMH