INSPECTORS will ask heads for details of recruitment difficulties from September.
As part of the inspection, the Office for Standards in Education will gather data from heads about the number of unfilled posts as well as jobs being covered by long or short-term supply cover.
Heads will also be asked if teachers are having to take classes outside their specialist area.
In his annual report earlier this year chief inspector Mike Tomlinson warned that staffing problems were the one thing that could endanger progress in raising standards in English schools.
Speaking at the Local Government Association's annual education conference in Liverpool this week, he said: "The statements will be part of the evidence against which inspectors will have to weigh their judgments.
But he warned: "We are not saying (if there are recruitment problems) that you don't put a school in special measures, but it is part of the context." He cited an example of a school with severe staffing problems that were down to senior management inaction. Another school in London was still judged to have serious weaknesses, which were not just down to its 14 unfilled posts.
His announcement came as the General Teaching Council approved a 10-point recruitment and retention plan, including a national survey of those leaving the profession next year.