Good head teachers are afraid that working in challenging schools may be "career suicide", a union leader says.
Inspection teams were not giving outstanding heads enough time to turn schools round, said Brian Lightman of the Association of School and College Leaders (ASCL).
Good heads in tough schools had lost their jobs within months of starting, he added.
Education Secretary Michael Gove said good teachers would be supported.
Mr Lightman said "too many ASCL members lost their jobs last year."
"They might have been able to get their schools where they needed to be if only they had been given a realistic timescale to do so with the right support," he told the ASCL annual conference.
Speaking afterwards Mr Lightman said that a survey by the union had shown that 120 heads had lost their jobs in a single 12-month period, adding that when Ofsted puts a school into special measures there are two preferred solutions - one is to turn it into an academy, the second is to replace the head.
He said that talented heads who had recently been hired to transform struggling schools were particularly vulnerable if they faced an inspection soon after starting as they would have not have had time to make all the changes needed.
"I am very worried that for many people it is becoming career suicide," said Mr Lightman.
He added that many outstanding heads and deputy heads were deterred from moving to tough schools "because of the pressure for immediate results".
"Head teachers are not commodities you can throw away and we are not exactly overwhelmed with applicants to lead the most challenging schools."
He called on the Chief Inspector of Schools, Sir Michael Wilshaw, to recognise this and to "put a stop to those teams who go into some of our most challenging schools, applying a deficit model of inspection which creates a culture of fear, high blood pressure and lost sleep as people await the dreaded phone call."
He added that he had been "deeply shocked" by an example from last autumn after a new head with a proven track record started work at a struggling school.
Opting for 'good' schools
His work had immediate results, but despite acknowledging this Ofsted inspectors who arrived within two months of his starting put the school into special measures, said Mr Lightman.
He added that the school is now being forced to join an academy chain and the new head may lose his job with the result that other would-be school leaders may decide in future to "only opt for 'good' schools".
Chris Robinson, who took over as head of a challenging school in Barnsley in January and is due for an Ofsted inspection any day, said she felt "very exposed at the moment - at some point the school will be outstanding, but not in nine weeks".
"It takes enormous courage to leave a job you have been successful in to take on a school in difficulties," said Ms Robinson.
Education Secretary Michael Gove was challenged on the subject earlier in the conference.
One head teacher told him she was passionate about her work in a school in a deprived area but feared that it would be "career suicide" for her to remain there.
Mr Gove said he wanted to encourage and support head teachers in schools like hers, adding "when people are making big changes, they need to have time".
He acknowledged that "there are great leaders in all schools, including challenging schools" and added that changes to the Ofsted framework were designed to focus inspections on the "value added" - how much progress pupils make from when they arrive at the school.
Ofsted chief inspector Sir Michael Wilshaw also told the conference that he was trying to raise the standard of inspection teams and wants more current heads to become inspectors, with just over half of inspection teams already including a serving school leader.
Sir Michael told head teachers that he had "huge admiration" for them. "Even more importantly, Ofsted will recognise and support you," he added.