A school has come under fire after it was revealed dozens of Year 12 students had ordered schoolies shirts branded with the phrase "the drunkest and the highest".

Unley High students in Adelaide have come home with the t-shirts featuring pictures of a bong, a goon bag and a "shoey" – beer being poured from a shoe - alongside the words "Unley Army".

A mother of an Unley student was "shocked" when her daughter brought hers home and told News Corp she was furious the shirts had been organised at the school.

She said the shirts have made her question her decision to allow her daughter to go to schoolies.

Unley High's Principal said she was "extremely disappointed" with the production of the t-shirts.

"This is totally unacceptable and senior leaders will work with Year 12s to help students understand why this is a poor decision that reflects badly on themselves, and on the school,” principal Brenda Harris said.

“While the school does not have oversight over schoolies, we encourage any students participating in any out of school celebrations to consider their personal safety and appropriate standards of behaviour.