The murder accused dubbed the Black Widow has been found guilty of fatally poisoning her second husband.
A jury of seven men and five women deliberated for seven and a half hours over two days before delivering their unanimous verdict in the High Court at Christchurch a short time ago.
Helen Milner, 50, had denied murdering Phil Nisbet, 47, by slipping the sedative Phenergan into his evening meal and, while he was heavily sedated, probably suffocating him.
The Crown had alleged she made his death, on May 4 2009, look like suicide in the hope of cashing in his $250,000 life insurance policy.
The defence argued that Mr Nisbet took his own life.
Milner was also found guilty of one count of unsuccessfully attempting to kill Mr Nisbet on April 15, 2009 but not guilty of a second such charge.
There were sighs of relief in the public gallery at the guilty verdict on the murder charge.
Milner was teary in the dock as she was led into the cells.
The judge thanked the jury for its efforts over the last 14 days.
Defence counsel Rupert Glover made no comment as he left court.
Outside court Kasey Woodstock, who testified against Milner, said: "She deserves everything she got - let her rot."
Mr Nisbet's youngest brother Andrew Nisbet addressed media on behalf of the family.
"The family would just like to thank the jury for the verdict. I'd like to thank Detective inspector Greg Murton for all the effort his team has put in, friends and family for supporting us.
"Finally, some justice for my brother after over four-and-a-half years. We now want to move on and look forward to a sentence that's going to be appropriate to this terrible crime."
Mr Nisbet refused to comment on the first police investigation which ruled his brother's death was a suicide, and not murder.
A homicide probe was launched two years later only after a coroner raised doubts about the decision.
The Crown and defence both wrapped up their cases yesterday after 11 days of testimony from more than 70 witnesses, including family, friends, workmates, police, professionals and medical experts.
In final arguments the jury was told the case boiled down to a choice between scientific and circumstantial evidence.
Crown prosecutor Brent Stanaway said it amounted to an "overwhelming circumstantial case".
Office administrator Milner had spoken so frequently about "getting rid" of her delivery driver husband, openly discussing methods and poisons, that she eventually "talked herself into it", he said.
But defence counsel Rupert Glover said it was not a case of murder by poison, but rather an assassination of Milner's character by "poisonous testimony". He urged the jury to look at the science instead.
Milner will be sentenced on February 20.