Kerri Imelda Doherty was supposed to see four offenders at least once a month, a Care Council for Wales (CCW) hearing in Cardiff was told.
The men needed regular visits because they could suffer a relapse which could put the public at risk.
Ms Doherty denied any wrongdoing but three allegations were found proven.
A fourth charge of acting "dishonestly" was found not proven.
The hearing was told Ms Doherty worked for Vale of Glamorgan council as a senior social worker and had years of experience.
Part of her job was to make sure people who had committed "significant crimes" but were living in the community, complied with Crown Court orders issued under the Mental Health Act.
Ms Doherty said visits had happened every six weeks but council mental health services manager Andrew Cole, giving evidence on the first of a two-day hearing, said the visits were less frequent.
"[This led] to a potential increased risk of somebody's mental health deteriorating and an escalation in their behaviour - which is more likely to go undetected," he said.
Mr Cole also said the minimum four-week frequency of visits was set by doctors and would have been "clearly marked" on official documents.
In her evidence, Ms Doherty told the panel she often had an excessive work-load, inadequate management support and often felt "left out on a limb".
The hearing was also told that bereavement had caused her to "burn out" and that her life had become "chaotic" as a result.
Ms Doherty, who had been subject to a suspension order since the allegations came to light in 2014, told the hearing she was not seeking to return to social care.
A report by the care watchdog said: "The committee finds that only a Removal Order will be adequate in this case given the seriousness of the impairment."
A social worker who failed to make regular visits to convicted criminals with mental health problems has been struck off.