Five students at a Melbourne high school have been suspended and will face counselling after teachers discovered they had laced cookie batter with marijuana during a home economics class.

The two year-eight pupils who were responsible for adding a "very small amount"of marijuana into cookie batter, and three students who bit the cookies but did not eat them, have been disciplined.

The principal, who has asked to remain anonymous in order to protect the students involved and to avoid encouraging "this kind of behaviour", said that "any student that bit into the cookie immediately spat it out, as it was unpalatable".

The parents of the children were called immediately, and the school held a meeting with all parties involved.

"The school takes all matters of this kind very seriously, and the students have been suspended.

"When the students return to school, they will be involved in sessions with our local Victoria Police youth resource officer, a drug and alcohol education officer and an adolescent health worker," the principal said.