It is Kenya’s first national vote since 1,300 people were killed in post-election violence in 2008.
Political leaders are hoping a ballot today on a new constitution will go some way towards making sure that such widespread unrest is not repeated.
Observers say the new law is aimed at tackling corruption, nepotism, land disputes and tribal tension, which have plagued the country since independence from Britain in 1963.
A previous attempt to change the constitution in 2005 failed.
Opinion polls indicate that most Kenyans are likely to vote in favour, giving the go-ahead for greater controls over presidential power, decentralisation of power and a boost to civil liberties.
A new constitution was central to a power-sharing deal struck to end the 2008 violence, an accord between the then rival president and prime minister.