The survey of 162 secondary principals found about a third of advertised teaching jobs had no suitable applicants and eight per cent of schools had no relievers, with the average number of relievers the lowest recorded.
There was a further jump in teachers being used out of their specialist area because specialists could not be found with more than 40 percent of schools having to do so this year - the highest recorded since the survey began. On top of that, 20 percent of schools had to cancel classes or transfer to a form of distance learning because a suitable specialist teacher could not be found - the highest level since 1998.
Schools mostly use teachers trained in PE, primary and social studies to cover classes, with the classes most covered by non-specialists being maths, English and science, the survey found.
Principals were more negative about the recruitment and retention of teachers than they had been since the end of the 1990 and of all the teachers who left the profession, 40 per cent were retiring.
NZ Secondary Principals' Council chairman James Morris described it as a "perfect storm".
"There is a wave of teachers about to retire and I'm embarrassed to say that we have reached the point where we are begging them to stay on, for another term, another year, until the crisis is over.
"Young graduates no longer want to enter the profession, the pay is far too low compared to what they earn in other careers and, of the new teachers who do enter the profession, nearly half burn out and leave within five years."