Half of all house fires in Perth and Kinross are happening in properties with no smoke detectors.
It comes as accidental house fires in the area hit their highest level in four years.
And the shock figures have emerged almost two years after interlinked smoke and heat alarms became a legal requirement in Scotland.
Perth and Kinross fire chiefs say crews dealt with 56 accidental house fires in the first six months of 2023.
Two people died, and 11 casualties were recorded.
Smoke alarms were fitted in 28 cases.
But only 22 of them gave early warnings.
In most cases, the fires started because someone in the home was cooking. Often occupants had been distracted, although alcohol and drugs were also a factor.
The figures were presented to a council meeting today.
Figures on Perth and Kinross house fires worrying
Members of the housing and social wellbeing committee were told the local Scottish Fire and Rescue Service is targeting vulnerable households with advice and support on linked alarm installations.
Firefighters make home safety and wellbeing visits. The service also reaches people through social media and engagement with carers.
But Perth City Centre councillor Peter Barrett asked what it and the Scottish Government is doing to reinforce the message that linked smoke and heat alarms are now required by law.
Mr Barrett said the figures were worrying.
“It is almost two years since linked fire alarms became a legal requirement,” he said.
“But fire alarms were only present in half of homes where fires started.
“More worryingly a quarter of those alarms didn’t work.”
Safety in householders’ hands
The law changed in Scotland last year.
As of February 1 2022, every home is required to have interlinked smoke and heat alarms.
The system means if one alarm goes off, they all go off.
Installation is the responsibility of homeowners.
But concerns have been raised elsewhere about uptake.
Fire chief speaks
Scottish Fire and Rescue Service Area Commander Jason Sharp is the local senior officer for Perth, Kinross, Angus and Dundee.
He said: “The Scottish Government introduced legislation in February 2022 stipulating that landlords and home owners would be responsible for fitting alarms to a new standard within their properties.
“We welcome these measures which support fire prevention and fire safety within the home and would advise anyone who has not already done so to have new standard alarms fitted at the earliest opportunity and to test them regularly because it can save your life.
“In the meantime, our teams will continue to work towards reducing risk for our communities here in Perth and Kinross and across Scotland.”