A Health and Disability Commissioner has found the Northland DHB failed to give adequate care to a man who died after knee surgery in 2009.
The 75-year-old underwent elective surgery and died five days later following a cardiac and respiratory arrest.
The DHB says it profoundly regrets what happened and admits the care the patient received was not to a high enough standard.
Commissioner Anthony Hill said the elderly man had several existing medical conditions and needed to be carefully monitored after the elective surgery.
Mr Hill said due to a combination of inadequate documentation and poor communication, orthopaedic and nursing teams failed to recognise the man's deteriorating condition.
He told Radio New Zealand's Checkpoint programme on Monday that the death is a reminder to doctors and nurses to get the basics right.
"These are themes that are frequent in the cases, they are common in the errors that we see in the health sector and this case is a salutary reminder to do the basics well."
The Northland DHB said it accepts that the standard of care was not high enough and the case has led to many procedural changes for the hospital.
Chief medical officer Dr Mike Roberts told Checkpoint that the hospital has done everything it can to stop this from happening again.
"I know that all of the medical and nursing staff involved deeply regret the fact that the care that was offered was not as good as it could have been, and the district health board has already apologised to the family for those shortcomings."