Mount Isa Mayor Tony McGrady said for the vote to be mandated, at least half of the city's voting population, 5352 people, needed to take part.

Of the 968 people who participated, 102 voted 'yes' to fluoridating the city's water supply and 866 voted 'no'.

"In normal circumstances we would say with figures like that the status quo will remain," Cr McGrady said.

"It was an exercise in democracy, people were given the opportunity to vote and only around nine per cent of the population turned out."

"People will interpret the results of this referendum as it suits their particular point of view but the reality is that council said unless there was 50 per cent plus one people voting it wouldn't be mandatory."

Cr McGrady said the council would not take the large majority of 'no' voters as an indication of the community's point of view, but would now leave the decision in the hands of councillors.

"Once you've had a referendum and there's been no overwhelming turnout to say yes or no... the status quo will remain," he said.

"If council by majority vote are determined to say yea or nay that will change things, but we've allowed the people to speak so each individual councillor has the chance to say yes or no if they want to."

The city's fluoride referendum was open each day last week, culminating with the largest voting day on Saturday.

Polls closed at 6pm on Saturday when all votes were counted and deemed to be valid.