Laws must be tightened to protect young women who are dating abusive men, it has been claimed.
Women's Aid has called on the Government to extend the Domestic Violence Act to cover those in relationships who are left unprotected due to strict co-habitation requirements.
The domestic violence charity also criticised gaps in the law that leave women who are being stalked, including being monitored or controlled by email, social media and mobile phones, unprotected and vulnerable.
Launching its 2in2u awareness campaign, which highlights the abuse of younger women who are dating, it revealed six out of 10 who suffered severe abuse first experienced it when they were under the age of 25.
Margaret Martin, director of Women's Aid, said young women do not need to be in a "domestic" relationship to experience domestic abuse.
"Abuse can happen to any woman, at any age and in any type of relationship, including dating relationships," she said. "Women's Aid's experience and national and international research shows that many young women are at risk from violence and abuse from their boyfriends."
Figures show that 39 young women aged between 18 and 25 have been killed since 1996. "Of the resolved cases, 53% of the women were murdered by their partners or ex-partners," Ms Martin added.
The charity's two-week campaign highlights unhealthy and abusive behaviour by young men and encourages victims to trust their instincts and take a relationship health check.
Anyone anxious or worried about their boyfriend's actions can answer a series of questions on www.2in2u.ie or call the Women's Aid helpline on 1800 341 900.
Women's Aid said some victims have reported being stalked and followed, with perpetrators turning up at their work, home and social gatherings, while more women are claiming to be tracked and abused by boyfriends and ex-boyfriends through mobile phone calls and texts often telling them, in explicit detail, how they will be attacked or even killed.