The revelation came during an inquest into the death of Gordon Gomersall, left, a former teacher from the school, who developed the fatal condition asbestosis – or mesothelioma – last summer.
The cancer is caused by inhaling particles of asbestos which can stay dormant in a victim's lungs for decades before a tumour is triggered.
Now his widow is calling for asbestos to be removed from all city schools.
A letter from Leeds City Council read out to Leeds Coroner's Court said that some asbestos removal at Templenewsam Halton Primary School, where Mr Gomersall taught for 20 years, took place in the late 1970s.
But a safety survey in June 2005 said there was still asbestos in the school built in 1944 including toilet seats, cisterns, ceiling and floor tiles.
These were deemed 'low risk' and not removed but abestos found in the boiler house and caretaker's store were a 'medium risk' and the areas cleaned.
Today the widow of Mr Gomersall, who died just two months after he was diagnosed with a tumour in his chest last July, called for asbestos to be removed from all schools in the city.
Barbara Gomersall, 72, from Crossgates, told the YEP: "If such a miniscule particle of asbestos is so dangerous and can lie 40 years or more before activating and causing such a horrendous death, surely it's time that all this so-called low risk asbestos is completely eradicated."
At the inquest Leeds Deputy Coroner Robert Chapman said Mr Gomersall had been exposed to asbestos somewhere which caused his cancer.
He recorded an open verdict, saying there was "no clear" evidence that it definitely happened to the father-of-two while he was at the school.
Mrs Gomersall, who was an infant teacher at the school, told the court that her husband worked there most of his career before taking early retirement.
She added that before his death the couple went through his life and couldn't think of anywhere else that the 77-year-old, who taught general studies from 1960 to 1979, might have come into contact with the deadly dust.
Tim Hales, health & safety advisor for the Leeds National Union of Teachers (NUT), said: "The NUT is campaigning and lobbying the Government and local authorities to get asbestos removed from all schools.
"Our latest figures show nationally there were an average of 22 teacher deaths a year from mesothelioma in the period 2002-2005. In the three year period before that it was 14 per year.
"Obviously our concern is that not only could our members and other school workers be exposed to asbestos dust, but also children."
An Education Leeds spokeswoman said that asbestos did not pose a risk unless it was damaged and exposed.
She added: "We take the safety of school buildings very seriously and have a programme of asbestos surveying work whereby frequent checks are carried out at all our schools.
"We also ensure every school has a plan in place for monitoring any asbestos identified in the checks and to ensure that it is sealed and safe."