In a major change of policy, teachers and students will share the same toilets at all schools under the Office of the Basic Education Commission (Obec).
The change has quickly drawn ire on a social media platform operated by the Education Ministry.
Obec secretary-general Thanu Wongchinda announced that in future there will not be separate toilets at schools for teachers and students, in a message posted on the ministry's Facebook account.
The statement came with hashtages, two of them saying #fromnowoneverythingmustbeequal and #studentsandteacherscansharetoilet.
Toilets will be separated only by gender, males and females, the official said.
The change was part of a plan for cleaner school toilets and was a policy of Education Minister Permpoon Chidchob. The minister "has assigned the BEC to improve school toilets nationwide so that students and teachers can share and they must be cleaner", the Facebook message said.
The minister had previously surprised people when he expressed admiration for the education system in North Korea and the strict discipline imposed on youngsters there.
Obec will start improving toilets firstly at its 9,700 small schools with no more than 80 students, and later at larger schools. However, the shared toilet policy will be introduced at all schools this semester, the official said.
A survey of students showed they wanted cleaner toilets at schools, according to Obec. "Toilets for teachers are heaven. Toilets for students are hell," the ministry quoted one comment made during the survey.
Ekkachai Keesukhaphan, a former Obec board chairman, criticised the plan, saying the commission is addressing the problem the wrong way.
Mr Ekkachai told Matichon Online that all toilets at schools, both for teachers and students, needed to be more sanitary, but students should also have respect for their teachers. Thai culture could suffer if there was no boundary between teachers and students, he warned.
The board functions as an adviser to the commission.
Comments posted following the ministry's announcement said students' toilets were dirty because the children made no effort to keep them clean or to help the school janitors, who were overworked.
"Private toilets for the exclusive use of executives should be available for use by teachers, students and other staff as well," one commenter wrote.