All the main political parties are represented, including the Union of Forces for Change (UFC), which has boycotted previous polls.
Togo, officially called the Togolese Republic, is located on Africa's west coast, bordering Ghana in the west, Benin in the east, and Burkina Faso in the north.
It has a population approximately 6.1 million.
1960: Togo gains independence under Sylvanus Olympio, the first president.
1963: Olympio is assassinated in a military coup by a group of soliders under the directions of Sergeant Etienne Eyadema Gnassingbe.
1967: Gnassingbe launched a bloodless coup and appointed himself as president.
1991: Political parties are legalised.
1992: A democratic constitution is adopted.
1998: A joint investigation by the UN and the Organisation of African Unity (OAU) concluded that elections this year resulted in 'systematic human rights violations'.
2005: Gnassingbe dies, after 38 years in power. He was Africa's longest serving ruler.
Faure Gnassingbe, his son, is appointed as president, provoking international condemnation.
According to the UN, at least 500 people are killed in violence surrounding the polls.
As many as 40,000 people flee to neighbouring countries.
The nearly 5,900 voting stations are scheduled to close at 5pm on Sunday.
Preliminary results will be made public several days after the vote, according to the Independent Electoral Commission.
Waiting for ink
In one polling station in one of Lome's secondary schools, the organisers were still waiting for indelible ink.
Essential equipment was also late in arriving at a primary school in the Hedzranawoe district of Lome, where long queues had already formed before 7am.
The vote marks the first time that the UFC, led by Gilchrist Olympio, is challenging the ruling Rally of Togolese People (RPT) in nearly 20 years.
The poll will test the RPT's hold on power and decide whether Togo will receive aid from the EU after a 14-year suspension.
The EU has urged all sides in Togo to observe political protocols agreed in previous talks and has deployed a team to monitor the fairness of the popular vote.
The RPT has based its campaign message on what Faure Gnassingbe, Togo's president, has achieved in the past two years with regard to improving relations between the ruling party and the opposition.
Gnassingbe was first put into power by the military in April 2005 after the death of his father Gnassingbe Eyadema, but he stood down shortly afterwards amid public dissastisfaction with the military.
Two months later he won an election that was boycotted by the political opposition, but his government has since managed to break a long-standing political deadlock.