But while many expect Kenyatta to prevail once again, his opponent and longtime rival opposition leader Raila Odinga remains hopeful.
Earlier in the campaign, the 55-year-old Kenyatta, who leads the Jubilee Alliance, had been expected to win easily -- but that no longer looks certain.
Defeat would prove doubly embarrassing for Kenyatta, who would become the first Kenyan President not to have won reelection.
With a week to go, all eyes are on the key candidates vying for the presidency -- two men whose fathers led Kenya to independence nearly 55 years ago. While there are eight candidates in the election, only Kenyatta and Odinga retain any real hope of winning.
Kenyatta, son of the country's first president, Jomo Kenyatta, has in turn accused Odinga, son of the Kenya's first vice president, of attempting to divide the country.
To win the election outright, either man must gain 50% of the votes, plus one -- as well as at least 25% of the votes in half of Kenya's 47 counties.
If no winner is declared, the election will go to a runoff, which would be a first in Kenya's history.
What are the big talking points?
Kenya's National Super Alliance (NASA) opposition leader and presidential candidate Raila Odinga poses during a presidential debate in Nairobi.
The election is largely being fought over the economy and the courting of the youth vote.
Kenyatta is promising to create 1.3 million new jobs, reduce the cost of living and create a more inclusive economy by reducing economic inequalities.
Odinga, 72, is promising to fight corruption, create jobs for young people and set up programs to improve food security.
Fears of violence?
A resident of Kibera runs with a sack of charcoal he stole past a burning shack as he and thousands of other looters swept through the slum ransacking stores and setting cars and other property on fire 31 December 2007.
Kenya's last election, in 2013, passed off peacefully, but 10 years ago the country was plunged into widespread violence in the aftermath of the 2007 vote.
More than 1,000 people were killed and 500,000 were displaced in months of bloodshed following the election, after Odinga -- who had been defeated by the then-President Mwai Kibaki -- claimed the vote had been rigged.
Opposing protesters loyal to each leader took to the streets, and protests escalated into bloody violence, fueled by decades of economic frustration and ethnic rivalry. The violence was not limited to supporters of the two political rivals -- other ethnic groups joined in and picked sides, adding to the chaos.
Supporters battled it out using machetes and other crude weapons in the worst violence the nation had seen since it gained independence from Britain in 1963. Hundreds of thousands were displaced, with some still living as refugees in their own country years later.
After more than a month of negotiations, former United Nations Secretary-General Kofi Annan mediated a power-sharing agreement in February 2008 that was signed by both leaders. It created a prime minister's office for Odinga as part of a power-sharing government.
In 2013, a breakdown in voter identification technology was the primary reason that Odinga contested the results of the vote, taking the case to Kenya's highest court, which ultimately ruled in Kenyatta's favor.
Before his death, Chris Msando, head of information at Kenya's Integrated Electoral Management System, led the department responsible for voter identification and