Following decades of campaigning, NSW has become the last state in Australia to pass these laws.

It means terminally ill people in NSW will be able to access voluntary assisted dying within 18 months.

The bill passed the lower house on Thursday afternoon to thunderous applause, after passing the upper house with amendments following a marathon 12-hour debate.

Ms Cohen said she watched the debate in the upper house until 9pm on Wednesday night before continuing watching the debate on Thursday morning.

"It's a huge relief and it's great news for anyone with a terminal illness and their families to have that reassurance that they do have an option if their pain and suffering becomes too great," she said.

"They now have a choice to die with dignity."

Ms Cohen was diagnosed with terminal cancer in 2015 and has been rallying ever since to gain the freedom to choose how her life ends.

"It's legislated that it's going to take 18 months for the scheme to be accessible and frankly it does take that long for all the processes to be put in place to ensure the scheme can operate as well as it can. And also for doctors to be trained," she said.

"I do hope that I'm going to still be around to be able to access the scheme in my own state."

The bill was introduced into the lower house last year by Independent MP for Sydney Alex Greenwich, with coalition and Labor MPs allowed a conscience vote on the issue.

Member for Port Macquarie Leslie Williams has been a long-time supporter of the bill and said she was "excited" to be chairing the house when the historic bill passed the Parliament of NSW on May 19.

"I know that so many people across the Port Macquarie electorate have been watching the debate closely over the past six months," she said.

"I applaud all the co-sponsors of the bill, but particularly my friend and colleague Alex Greenwich."

The bill allows adults with a terminal diagnosis and up to six months to live to voluntarily end their life with assistance, based on the approval of two independent doctors.

Ms Cohen said although today is a celebration for many, it is also a day to remember those who aren't here to see the historic bill pass.

"Today is tinged with sadness too because unfortunately a lot of people have died in pain and suffering while waiting for the bill to pass," she said.

"The bill passing is a great reason for celebration, but we mustn't forget all those people who fought so hard and who are no longer with us."

Ms Cohen has been campaigning for the right to choose how how her life ends for seven years.

"The bill passing reminds me of the power of a grassroots campaign and an affirmation of people power and the democratic process.

"Compassion and the facts won the day, along with community support."

*If you are thinking about suicide or experiencing emotional distress, help is available.

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