A partial defence of "killing in an abusive domestic relationship'' was added to the Criminal Code and goes beyond the present defences of provocation and self-defence.
The clause will provide battered partners some immunity in court and give judges greater discretion when sentencing on the charge of murder.
Attorney-General Cameron Dick said Queensland was the first Australian state to provide the partial defence.
The amendment included safeguards to ensure it only applied to those who had suffered severe domestic violence leading up to the killing, he said.
In order for the defence to apply, accused people will have to prove they had been in an abusive domestic relationship and the person they killed had committed acts of serious domestic violence against them during the relationship.
At the time of the killing, the accused must have believed their acts were necessary to avoid death or grievous bodily harm and that there were reasonable grounds for this belief.
Mr Dick said the changes marked an important step in the protection of Queenslanders' rights and recognised the need to provide legal protection to "genuine victims'' of domestic abuse.
"Research reviewed during the development process found that victims of seriously abusive relationships often commit offences in circumstances that fall outside existing defences, such as self-defence and provocation,'' Mr Dick said.
"This defence will be available for victims of serious domestic violence where all the necessary criteria for its use have been met.
"It doesn't excuse victims but it does broaden the court's sentencing options.
"The defence is framed in a way that will ensure it is reserved for genuine victims and not misused.
"This represents a balance between necessarily punishing those who would otherwise be guilty of murder while providing some legal protection for victims of serious abuse.''
The state government put the provocation defence under review in 2007 after a Gold Coast man charged with murdering his girlfriend in a fit of jealous rage argued he was provoked and was convicted of the lesser charge of manslaughter.
The government consulted the Queensland Law Reform Commission, academics and other key stakeholders in the judiciary, the legal profession and the community when drafting the law, Mr Dick said.
The Criminal Code (Abusive Domestic Relationship Defence and Another Matter) Amendment Bill 2009 also includes amendments to increase protection against identity theft by creating the new offence of possessing equipment for the purpose of obtaining or dealing with identification information.