Auckland District Health Board chairman Pat Snedden says the firm providing all community medical testing for the region has gained international accreditation.
Labtests took over testing in the region from former provider, Diagnostic Medlab Limited in September.
The company has been under scrutiny since quality and safety issues were raised about its service.
Mr Snedden acknowledges that there were some problems before Christmas, but says Labtests' accreditation shows that a line can now be drawn under those concerns.
He acknowledges, however, that more work needs to be done on the long-term relationship between Labtests and clinicians to rebuild trust.