That is according to a report by the Northern Ireland Association of Social Workers (NIASW).
Its findings show staff are working above and beyond what they are paid to do, in teams where there are vacancies, to ensure the public aren't at risk.
The association says it will present the report to the minister for health.
Nearly nine out of 10 of those who replied said they worked extra hours with no extra pay.
The burden of paperwork and lack of administrative support were said to be among the greatest challenges for staff.
Social workers also highlighted the growing complexity of cases and the need for greater support from their employers.
Donna Murphy has been a social worker for 20 years.
She is the principal practitioner for child protection in the Southern Health & Social Care Trust and says her job has become increasingly complex.
"A tough day would be the unexpected. I may be going to a routine call to a family home, knock on the door and not really know what I'm going to find behind it.
"I may get into the family home and find chaos, a parent who may be under the influence of alcohol, maybe subjected to domestic violence the night before and children who are distressed as a result of that incident.
"There may be children as young as babies in cots and maybe an aggressive father who doesn't want me in that house to see what is going on."
400 of Northern Ireland' s 5000 social workers took part in the online survey.
Those who responded said there was not enough cover for those on maternity leave and long term sick leave.
The NIASW says it is recommending that employers undertake an audit to establish the number of additional unpaid hours worked by staff. They also want an audit of vacancies to be conducted and filled as a matter of urgency.
Its country manager Carolyn Ewart says that although the survey has revealed quite a bleak picture, the public are not at risk, because the profession will pick up the extra work.
"The difficulty is not just for social workers, but also for service users in that the staff who remain in the team are required to take on the extra work and people within the team do that because they want to provide a seamless service," she said.
Social workers in Northern Ireland are having to work additional unpaid hours in order to meet the needs of the public.