The prostitution takes place in an open veld a few metres from the Hoërskool Pretoria-Wes.
The sex workers have now built small tents order to ply their trade.
Residents have been grumbling about the issue but say little action has been taken of late.
Prostitutes had been operating in the area for years, Hoërskool Pretoria Wes principal Hannlie Coetzee said this week.
“There’s a lot of them (prostitutes) just near the school and they operate anytime of the day and night,” she said.
“It has been going on for the past 15 years I have been the principal at the school.”
Police had chased them away several times but they kept on coming back.”