Disheartened by the increasing number of pregnant classmates , 10 pupils in the small town of Kuruman, in Northern Cape, decided it was time to act.
Said Lerato Mooko, 17, one of the 10: "We had to learn all about the Sexual Offences Amendment Act."
Teacher Tsepo Kgatlhane, the girls' project manager in their endeavour, said men who worked on the mines nearby often preyed on schoolgirls who "did not know any better".
The schoolgirls launched Standing Together Against Rape Bua, or Star Bua ("Bua" is Tswana for "speak") to protect girls and bring sexual predators to book.
The campaign took top honours at the Empowervate Trust Youth Citizens' Action Programme national championships in Durban last weekend.
Said Tlaleng Ketumile, 16: "We also want to change the idea that it is only rape when it is violent, and encourage young people to share their personal stories to help other victims to heal."
The girls, aged between 15 and 17, use Facebook to spread their message.
They have called on fellow pupils to sign a petition against rape and have initiated a "walk a mile in her shoes" day, during which boys wear high heels to gain some feeling for what women go through.
They have also organised a silent protest against the abuse of women and girls.