A woman charged with killing her de facto partner has been found not guilty of murder and not guilty of manslaughter.

Lena Kasparian, 33, admitted to stabbing Marc Zartarian at their home at Wetherill Park in south-west Sydney on May 1 last year, but pleaded not guilty to murdering him on the grounds of self-defence.

Relatives of Mr Zartarian screamed and abused Ms Kasparian after the jury's verdict was read out today.

"I hope your children die the same way," a woman yelled towards Ms Kasparian.