Two pathology services have imported new technology to minimise lab specimens being mixed up and patients misdiagnosed.
A Ministry of Health report in 2012 showed three women had mastectomies due to incorrect diagnoses.
In response, Pathlab has installed the first automated electronic monitoring system of samples in New Zealand.
Dr Richard Massey of Pathology Associates Ltd, Pathlab's parent company, said it's the first time the system's been used in the Southern Hemisphere.
He said it means the opportunity for human error is minimised.
Aotea Pathology is introducing a similar product.