Staff at Northumbria NHS Foundation Trust walked out for 48 hours in July in a dispute over wages.
Unison Northern regional secretary Clare Williams said: ‘It's great to see these low-paid health workers win their hard-fought campaign for fair wages and proper recognition of the years they've dedicated to these roles.
‘It should never have come to strike action, but it's good the trust returned to negotiations and agreed to the back pay staff deserve.
‘The union will now work to get health workers the money they're owed.'
The deal was struck after Unison argued healthcare assistants had been paid at band 2 of the NHS Agenda for Change pay scale, despite increasingly carrying out clinical tasks that should be paid at the higher band 3 rate.
The workers had also campaigned for several months to secure fair back pay for the work they had already undertaken.
Unison said similar pay awards for healthcare assistants have been won at North Tees and Hartlepool NHS Foundation Trust, South Tees Hospitals NHS Foundation Trust and South Tyneside and Sunderland NHS Foundation Trust.
A spokesperson from Northumbria Healthcare NHS Foundation Trust said: ‘We are pleased that we have reached this resolution as this is a positive outcome for our health care assistants, wider team and our patients. We continue to acknowledge and appreciate the vital role that our health care assistants have in providing care.'