South Australia's declared drug trafficker law targeting repeat offenders and stripping them of "all assets" has passed State Parliament.

Attorney-General John Rau said the law was needed to "attack" the state's drug problems at the source.

The new legislation aims to target high-level repeat offenders and strip them of "all assets whether or not acquired from proceeds of their crime".

A dealer will be considered a declared drug trafficker if found guilty of three indictable drug offences over 10 years — excluding time in jail — or if found guilty of trafficking a commercial quantity once.

A commercial quantity includes 500 grams of amphetamine, 2.5 kilograms of cannabis, 100 cannabis plants, 2 kilograms of cannabis resin, or 200 grams of heroin.

The Act allows for the confiscation of all of a declared drug trafficker's property, whether or not it is established it was lawfully acquired.

The assets can be held pending prosecution of matters before the court.

The confiscated assets will be paid into a Rehabilitation Fund which is "devoted to programs and facilities for the benefit of victims, offenders and other persons", a Government statement said.

The Criminal Assets Confiscation (Prescribed Drug Offenders) Amendment Bill first started life in Parliament in 2011, before it returned to the Lower House and passed yesterday.

"Drug crime is all about money and we are determined to take the money off the big dealers," Mr Rau said.

"We have pursued this policy over the past five years because it will cause serious damage to this evil trade.

"The only way to tackle drugs on our streets is to attack the problem at its source. These new laws attack the supply side and the criminal networks which prey on South Australians," he said.