Melbourne has once again been named the world's most liveable city by The Economist, receiving a perfect score for healthcare, education and infrastructure.

The Economist Intelligence Unit's (EIU) Liveability Index ranks 140 cities each year on those topics, as well as stability, culture and environment.

Top five most liveable cities: 1. Melbourne 2. Vienna 3. Vancouver 4. Toronto 5. Adelaide, Calgary

Vienna once again came second and Vancouver third.

Adelaide was the next best Australian city finishing in fifth spot, followed by Perth at number seven. Sydney was ranked 11th.

It was a record seventh time in a row in the top spot for Melbourne, which scored 97.5 out of a possible 100.

The top five remained unchanged from last year.

City of Melbourne Lord Mayor Robert Doyle said the EIU's index was the most widely accepted city rankings system.

Mayor Robert Doyle said the city did not take the accolade for granted. ( ABC News: Margaret Burin )

"This world record is an amazing feat that all Melburnians should be extremely proud of today," Cr Doyle said.

"This accolade is an important selling point for Melbourne internationally: for businesses to invest or move here, for the best and brightest people to make Melbourne their home and for tourists to visit us.

"There will always be naysayers and whingers, and of course we are not perfect. No great world city is, but we should be very proud of the work we all do together to make Melbourne the best city in the world."

Low crime rate gets Melbourne across the line

The report said the ongoing threat of terrorism around the world affected a number of scores.

It noted Melbourne's relatively low crime rate as one of the main reasons it outranked other high-performing cities, despite an increase in robberies and thefts in the last 12 months.

However, Melbourne is not without its problems.

The city has been struggling to deal with a rising and increasingly visible homelessness crisis, with more people sleeping rough in the CBD than ever before.

There's been an increase in the number of rough sleepers in Melbourne. ( ABC News: Margaret Burin )

The issue of housing affordability is also causing stress as property prices continue to rise, locking many out of being able to afford their own home.

The price of renting is also high, with almost all suburbs considered unaffordable for those on low incomes.

Public transport is also bursting at the seams. Last month, the entire train network ground to a halt during peak hour after a computer glitch.

Rating 'glosses over realities of life in Melbourne'

Victorian Council of Social Service chief executive Emma King said the Economist's index painted a distorted picture of life in Melbourne.

"These blunt measures gloss over the realities of life in Melbourne for many people," she said.

"Did The Economist survey anybody who's living under a bridge or skipping meals to pay their power bill?

"Melbourne is a great city. But, for many, it provides anything but an easy life."

But the Victorian Government spruiked the city's "world-class health care system" and strong economy, saying 100,000 new jobs were created in the state last year.

"There's a buzz about the city that keeps bringing the world's best to enjoy Melbourne," the Government said in a statement.

"The biggest exhibitions, the best events, world-renowned restaurants and all-night public transport to get you home safe."