More than 6,000 people targeted by criminals were supported by volunteers last year.
The National Crime Victims Helpline revealed there was an 11% rise in the number of cases it dealt with in 2011 as people left feeling vulnerable or anxious came forward.
Co-ordinator Maeve Ryan said more than 17% of calls related to physical assaults - particularly unprovoked assaults on the streets late at night. She warned that if there is no CCTV or witnesses it can be very difficult for the Gardai to trace the perpetrators and bring the attackers to justice.
"We encourage anyone who has become a victim of crime to talk about the incident to someone," she said. "Every day we help people who are experiencing emotional and practical difficulties, as a result of a crime."
The National Crime Victims Helpline helps people who are feeling isolated, anxious, angry, sad, nervous and afraid as a result of a crime to find emotional support on the phone.
A team of volunteers also answer questions about the justice system and give information on local services in their area.
Ms Ryan said there is no specific reason why the number of calls increased over the past 12 months.
"It may simply be that there is a greater awareness of the service," she said. "Our confidential service assists all those who call, irrespective of the reason why the person is affected.
"Some people for example, find that they feel afraid and vulnerable following a crime; some are upset by their experience with the criminal justice system and others face financial difficulties as a result of the crime.
"Crime Victims Helpline volunteers provide support and information to help each caller deal with the very individual problems that arise for them as a result of crime."