Victoria will investigate end-of-life options with a parliamentary inquiry set up to report by March next year.

Voluntary euthanasia and palliative care will be investigated after a collection of unlikely bedfellows joined forces to vote for a Victorian parliamentary inquiry.

The upper house voted to send end-of-life care to an inquiry, after an original bid to send it to the Victorian Law Reform Commission didn't get up.

Greens, Labor and Liberal MPs joined the Sex Party, the Shooters and Fishers, and the Democratic Labour Party to vote for the motion.

"Voluntary euthanasia is at the heart of any inquiry into end-of-life choices, and we are proud to have delivered this significant step forward," Green MP Colleen Hartland said on Thursday.

Sex Party MP Fiona Patten said having the support from MPs at wildly different ends of the political spectrum showed the inquiry would be fruitful.

"It's grown into something bigger, it's now a whole end-of-life inquiry," she said.

"We're looking at advanced directives, we're looking at palliative care, we're looking at dying with dignity."

The inquiry will deliver a report back to the parliament by the end of March next year.