Fourteen candidates are in the running, including 1992 Nobel Peace Prize laureate Rigoberta Menchu, a native Mayan advocate of indigenous rights and arguably the most renowned contender.
The likeliest victors, however, are Alvaro Colom, a businessman with leftist leanings, and a former general, Otto Perez Molina.
The presidential campaign in the Central American country, which suffered through a 36-year civil war between 1960 and 1996, has been one of the bloodiest in the country's history.
Nearly 250,000 people died or went missing in the struggle between leftist rebels and successive military governments.
In recent years, the country of 13 million has become a major transit route for Columbian cocaine to the United States, and the resulting violence has made it one of the deadliest countries in the world, with over 6,000 murders committed last year, the majority of which have gone unsolved.
Pre-election violence has been attributed largely to armed groups and drug traffickers seeking to influence political life.
All of the candidates, none of whom are expected to win outright the 50% support needed to avoid a run-off, are campaigning on platforms of law and order, promising to bolster the country's police force, fight official corruption and reduce poverty.
