The ballot, which is non-binding, included six questions written by the Constitutional Council, to which voters could either respond ‘yes’ or ‘no’. The vote was held on Saturday (19 October).
The process to draft a new constitution began after the country's 2008 financial meltdown prompted calls for reforms (see background).
A new basic law is due to replace the existing Constitution from 1944, which is largely inspired by the Danish constitution of the time and is seen as anachronism. Iceland used to be a colony of Denmark.
In July 2011, the Constitutional Council presented its draft to Parliament. The text, consisting of 114 articles, has been put together with feedback gathered via social networking websites Facebook and Twitter. News media have dubbed the new Icelandic basic law as the world's first "crowdsourced constitution".
Backers of change hope that politicians will not ignore the referendum, even though parliament is responsible for adopting a new constitution and the main opposition party has said it opposes proposed changes.
Initial results showed that 66% of participants voted in favour of a Constitution drafted by the Council. Nearly half of the island's 235,000 eligible voters participated.
Residents also voted to allow the Evangelical Lutheran Church to retain its role as state church (see the vote result to all six questions).
Valgerður Bjarnadóttir, who chairs the Icelandic Parliament's Administration and Supervision Committee, says a bill for a new Constitution could be ready within two weeks.
The bill would be presented to Parliament for debate before being put to a vote, a process she believes could be finished before the parliamentary elections in the spring. Voting on a new Constitution, she said, could be held alongside the elections.