One-year-old boy present when mother allegedly stabbed a man

A one-year-old baby boy was in the house when his mother allegedly stabbed a man in the chest at Vale Park in Adelaide.

Her son has since been removed from her care and placed with relatives.

Emotions were high on Wednesday morning outside the Stewart Avenue home where the stabbing happened.

Police allege the woman knew her victim.

Witnesses say the victim, aged in his 40s, lives interstate but had been staying at the home.

"I just heard screaming all of a sudden in the kitchen," Rhonda said.

"I rushed quickly and I seen what happened and I quickly put a towel to where he got stabbed, putting pressure on it till the ambulance came."

Another witness told 7 News: "We seen blood, blood was all over the floor and the wall."

The victim remains in a serious but stable condition in hospital.

A 21-year-old woman was arrested at the scene and has been charged with aggravated assault causing serious harm.

The woman's mother arrived home just hours after her daughter was taken into custody.

"She just called me yesterday to come, it was like an emergency," Katrina said.

"She never did anything to me, she just said emergency."

A knife allegedly used in the attack has been seized by police.