Women's Aid claims that violent men are using access visits to abuse their ex-partners and even their children.
The organisation says more than 5% of callers to its helpline last year were abused during such visits.
It claims access visits give abusive men an opportunity to "get back" at their former partners.
A total of more than 12,000 calls were received by the Women's Aid helpline last year, the majority from women reporting emotional abuse.
Physical and economic abuse were also factors in many calls.