An Iraqi refugee who stabbed his wife dozens of times before trying to hang himself has been sentenced to serve at least 17 years of a life imprisonment term.

Najeeb Dawood Dawood's life was saved when neighbours in the Wellington suburb of Strathmore cut him down but they were unable to save his wife of more than 20 years, Eman Jani Hurmiz, 41.

Dawood, 52, had originally intended to "deface" and "mutilate" his wife.

But the plan changed to killing her when she was lured to a shed at their Strathmore home and Dawood started attacking her, his lawyer Mike Antunovic said in the High Court at Wellington today.

Dawood had been on bail for earlier threatening his wife with a knife when he killed her on September 2, 2011.

In May last year he pleaded guilty to having murdered Hurmiz but his sentencing was delayed while lawyers and psychiatrists tried to agree on whether Dawood's jealousy was delusional to the extent of being a mental condition to be taken into account at his sentencing.

Dawood had been jealous and violent to his wife through much of his marriage.

Prosecutor Tom Gilbert said it had been a very brutal end to a controlling and violent relationship.

But Antunovic said Dawood had not only been delusionally jealous of his wife but also going through a severe depressive illness.

Justice Forrie Miller said that in the circumstances Dawood's condition did not justify a substantial deduction to the minimum jail time he must serve.

Hurmiz and their four children had come to New Zealand as refugees in September 2008. Dawood arrived in January 2010 and was said to have not settled well in New Zealand.

In November 2010 he was arrested for threatening to kill his wife, which he denied. He was still on bail for that and other charges when nine months later he stabbed his wife 55 times. He had tried to restrain her and had begun the attack by taping one of her wrists to a chair.

During the killing the couple's eldest daughter tried to break into the shed through a window to help her mother but retreated when she was stabbed in the leg. The screams drew her brother to the shed.

Hurmiz pleaded with Dawood not to let their two oldest children, both in their early 20s, see what he was doing. He pushed her to the ground and kept stabbing.

- © Fairfax NZ News