An ice-cream parlour owner dubbed the "ice lady" for the calculated way in which she killed her ex-husband and lover was sentenced to life in a secure mental institution.
Estibaliz Carranza, 34, had confessed to shooting the two men at close range in the back of the head.
She cut up their bodies with a chainsaw, freezing them in a deep freeze and later burying them in concrete under the cellar of her shop.
Judge Susanne Lehr told a Vienna court her confession and her state of "considerable psychological damage" were mitigating factors.
The judge held that her careful planning and her behaviour after the murders counted against her.
Carranza did not react to the unanimous jury verdict and nodded to confirm she had understood the sentence.
Her celebrity lawyer Rudolf Mayer, who also defended Austria's most notorious living criminal, Josef Fritzl, immediately said he would appeal to have the verdict overturned.
The Mexican-Spanish immigrant, whose case has attracted extensive interest from Austrian media, shot dead her German ex-husband Holger Holz with a .22-calibre Beretta pistol in 2008 as he sat as his computer.
Carranza said he had completely changed after their wedding.
She said he had turned verbally abusive, lazy and joined a Hare Krishna sect.
The defendant complained that he had refused to move out when she had a new lover, even after their divorce.
The new lover, ice-cream machine salesman Manfred Hinterberger, suffered the same fate two years later.
He received four shots in the back of the head as he lay in bed snoring after she had tried to start a discussion about his infidelity.
Carranza had taken courses in shooting and concrete-mixing before the killings, the court heard this week, and joked with a friend about her murder fantasies.
She wept as she told the judge: "All I can say is that I'm sorry I took the lives of Holger and Manfred."
Earlier, prosecutor Petra Freh told the court Carranza was a manipulative liar prepared to do anything for her own advantage, according to the Austria Press Agency.
Psychiatrist Heidi Kastner, who spent more than 30 hours with Carranza before the trial, said the murderer had a "grave, comprehensive, multi-faceted personality disorder".
She added that she was at considerable risk of killing again if she did not have therapy.
Dr Kastner was also the expert psychiatric prosecution witness in the 2009 Fritzl case, spending four months with him before the trial that ended in his conviction for rape, incest, kidnapping and enslavement of his daughter over 24 years.
The remains of Carranza's victims were found by chance last year when maintenance work was being done in the building where she had buried them.