As SA remains the last state in the nation to decriminalise abortion, hundreds have rallied to give local MPs a push to support bills before parliament.

A bill to reform South Australia's abortion laws will be presented to state parliament early next year, Attorney-General Vickie Chapman has said.

Greens MP Tammy Franks was sent a message from Ms Chapman, which was read aloud to hundreds of abortion decriminalisation activists who rallied in Adelaide's CBD on Saturday.

The march called for politicians to support two bills before the state parliament.

According to Ms Chapman's message, she received the final report from the SA Law Reform Institute with a number of recommendations.

"I will now commence work on considering all recommendations with the Minister for Health and Minister for Women with a position being released in early December," Ms Chapman's message read.

"From there, a bill will be produced and brought to parliament in the new year."

Ms Franks first brought the bill to parliament, which would remove abortion from the criminal code, late last year.

It was then referred to the SA Law Reform Institute and received 3000 submissions.

If the bills before parliament are passed, abortion would be decriminalised and safety zones where abortions are provided would be enabled.

"We have 50-year-old laws that put abortion on the criminal code where you can place up to life imprisonment," Ms Franks said.

"Our laws are no longer fit for purpose."

The South Australian Abortion Action Coalition organised the rally and spokesperson Brigid Coombe said abortion was an essential health care service and should be regulated like other health care procedures.

"One in three South Australian women will have an abortion in their lifetime," Ms Coombe said.

"It's essential our politicians listen to women's lived experiences and get this reform right to bring South Australia's laws into line with 21st Century health care."