Official figures obtained by Newshub reveal 75 teachers have been censured and 54 have lost their registration in the past three years for violations including sexual misconduct, assault and sex abuse.
It comes as 10 teachers in September went before the Education Disciplinary Tribunal for violations ranging from inappropriate relationships with students to fraud.
PPTA president Angela Roberts says it's important for the Education Council to monitor the statistics to pick up any trends.
"They may find that there is an increased trend of teachers who are suffering from significant stress, and some really poor decisions get made," she told Newshub, "and if that's something they see a trend is coming through on, then actually how do they respond to that?"
She says it's important the Education Council has good processes in place to protect teachers and students, as issues can rapidly get thorny.
"It can get really complicated very quickly - do the police need to be involved, is it just an employment issue or is it a registration issue? So there are three bits to it."
The Education Council told Newshub the number of convictions for serious misconduct is low compared to the 100,000 teachers there are nationwide.
It believes the increase can be attributed to more transparency in its reporting.