Fiji's National Council of Women says a change to the legal marriage age will help end the exploitation of young women.
The interim government has amended the marriage act by a decree which makes 18 the age at which both women and men may marry without parental consent.
Previously women could marry with their parents' consent at 16 and without at 21.
The council's president, Tauga Vulaolo, says at 16 girls are still at school and not physiologically ready to have children.
"It's a problem world over. We also have teenage pregnancies and we hope that part of this will be controlled to parents being more aware of the fact that their children are not so sexually active and with the law being put into place we hope that parents will be considering this and also the young women themselves."
Tauga Vulaolo says the council also hopes the law change will stop young women from being trafficked to other countries.